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BULLETIN 



Vo!. XV 


/ERSITY 


OF ILLINOIS 

Issued Weekly 

MARCH 4, 1918 


0 


No. 27 


[Kntered as second-class matter Dee. 11, 1912, at the Post Office at Urbana, HI., under the Act ol Au^;. 24, 1912] 


THE STORAGE OF BITUMINOHS COAL 


BY 

H. H. STOEK 



ClBCULAB No. 6 

ENGINEERING EXPERIMENT STATION 

Published by the University op Illinois, Urbana 

Price: Forty Cents 
European Agent 
Chapman & Hall, Ltd., London 
















HE Engineering Experiment Station was established by act of 
the Board of Trustees, December 8, 1903. It is the purpose . 
of the Station to carry on investigations along various lines 
of engineering and to study problems of importance to professional 
engineers and to the manufacturing, railwi\ mining, constructional 
and industrial interests of the State. y \ 

The control of the Engineering Experi^L^t Station is vested 
in the heads of the several departments of the College of Engineering. 
These constitute the Station Staff and, with the Director, determine 
the character of the investigations to be undertaken. The work is 


carried on under the supervision of the Staff, sometimes by research 
fellows as graduate work, sometimes by members of the instructional 
staff of the College of Engineering, but more frequently by investi¬ 
gators belonging to the Station corps. 

^The results of these investigations are published in the form of 
bulletins, which record mostly the experiments of the Station’s own 
staff of investigators. There will also be issued from time to time, in 
the form of circulars, compilations giving the results of the experi¬ 
ments of engineers, industrial works, technical institutions, and gov¬ 
ernmental testing departments. 

The volume and number at the top of the title page of the cover 
are merely arbitrary numbers and refer to the general publications 
of the University of Illinois: either above the title or below the seaT\ 
is given the number of the Engineering Experiment Station bulletin 


.or circular which should be used in referring to these publications.' 
For copies of bulletins, circulars, or other information address tl 


Engineering Experiment Station,® 
Urbana, Illinois. 




UNIVERSITY OF ILLINOIS 
ENGINEERING EXPERIMENT STATION 


Circular No. 6 


March, 1918 


THE STORAGE OF BITUMINOUS COAL 





H. H. STOEK 

% ' 


Professor op Mining Engineering 


ENGINEERING EXPERIMENT STATION 

Published by the University op Illinois, Urbana 


i > ” 1 
> > 

» > ) 






CONTENTS 


PAGE 

1. Introduction . 7 

1. Preliminary Statement . . . ,. 7 

2. Acknowledgments. 9 

3. Summary of Conclusions. 9 

t 

11. Reasons for Storing Coal .14 

4. Present Mining Conditions.14 

5. Benefits of Storage.15 


III. Places of Storage for Different Purposes ... 18 

6. Storage near the Point of Consumption.18 


7. Storage for Domestic Use and for Small Power Plants 18 

8. Storage by Railroads.22 

9. Storage at the Mine.23 

IV. Coal Storage Practice .26 

10. Kinds and Sizes of Coal which may be Safely Stored . 26 

11. When Coal should be Stored.28 

12. Storage Piles.29 

13. Ventilation of Coal Piles.31 

14. Testing for Fires.'.34 

15. Handling Fires.35 

16. City Ordinances Affecting Storage.36 

V. Storage Systems .39 

17. Choice of a Storage System.39 

18. Hand Operated Storage Systems.40 

19. Storage by Motor Truck.40 

20. Pile Storage from Cars without a Trestle .... 47 

21. Trestle Storage.48 

22. Storage with Side Dump Cars.51 


2 


p. of D- 

JUU 14 19*8 

It :" 6 


• « 



























/ 

jjxf 
c ' 'f'l 

CONTENTS (Continued) 

PAGE 

23. Side Hill Storage.56 

24. Self-filling Buckets.56 

25. Use of Mast and Gaff Arrangement in Storage . . 56 

26. Locomotive Crane Storage. . 59 

27. Parallel Track Storage . .^.63 

28. The Trestle and Crane Sj^stem.63 

29. Circular Storage.67 

30. Steeple Towers.75 

31. The Hunt System ..75 

32. Bridge Storage.76 

33. Deep Reinforced Concrete Storage Bins . . . . 86 / 7 ^ 

34. Under-water Storage.86 

VI. Effects of Storage upon the Properties of Coal . 107 

35. Appearance.107 

36. Loss of Heating Value.107 

37. Firing Qualities. 112 

38. Spontaneous Combustion . . ’.114 

39. Coking and Gas Making Properties.118 

40. Degradation or Breakage.120 

41. Loss in Weight. 127 

VII. Expense of Storing Coal.127 

Appendix I. Questionnaire on Coal Storage Data . . 130 

Appendix 11. Summary of Conclusions and Suggestions 

Regarding Coal Storage.132 

Appendix III. Experiences of Firms and Individuals Stor¬ 
ing Coal. 159 

42. Storage for Domestic Use and by Coal Dealers . . 159 

43. Light, Heat and Power Companies.165 

44. Storage at Metallurgical Plants.171 

45. Storage for Coke Ovens and Blast Furnace Plants . 172 

46. Mine Storage.175 

47. Storage by Railroads.178 


3 




















LIST OF FIGURES 


NO. 


PAGE 


1. Method of Ventilating Coal Piles Employed by the Canadian Pacific 

Railway. 

2. Coal Storage Plat and Storage Pile at the University of Illinois . 

3. Placing the First Layer of Coal on Storage Plat at the University of 

Illinois. 

4. Placing the Second Layer of Coal on Storage Pile at the University of 

Illinois. 

5. Electrically Operated Wagon and Truck Loatler Used at the University 

of Illinois. 

6. Railroad Storage Pile Showing Tracks. 

7. Railroad Storage Pile Showing Crib for Supporting Track .... 

8. Railroad Storage Pile Showing Men at Work Raising Track .... 

9. Trestle for Coal Storage as Suggested by Fuel Station Committee of the 

International Railway Fuel Association. 

10. Trestle and Tunnel Systems, Showing an Above-ground and a Below¬ 

ground Tunnel. 

11. Bin and Tunnel Type of Storage System with Bulkheads. 

12. Parallel Trestle System of Storing Coal. 

13. Storage Track and Side Dump Cars at the Orient Mine of the Chicago, 

Wilmington and Franklin Coal Company. 

14. Loading Dump Cars at the Tipple, Orient Mine of the Chicago, Wil¬ 

mington and Franklin Coal Company . 

15. Side Hill System of Storage. 

16. Clam-shell Bucket and Orange-peel Bucket. 

17. Automatic Grab on Mast and Gaff with Shuttle Cable Railway . 

18. Traveling Cableway. 

19. Locomotive Crane with Clam-shell Bucket Unloading Coal .... 

20. Arrangement of Tracks and Storage Piles Employed by the Common¬ 

wealth Edison Company in Open Storage. 

21. Parallel Track Storage System. 

22. Railway Trestle and Crane System of Storage. 

23. Locomotive Crane Placed on an Elevated Traveling Platform .... 

24. Dodge Type of Circular Storage System . 

25. Twenty-five-Thousand-Ton Storage Plant. 

26. Arrangement of the Storage Plant of the Old Ben Coal Corporation at 

West Frankfort, Illinois. 


32 

43 

43 

44 

44 

45 

45 

46 

49 

51 

52 
52 


53 


53 

54 

55 
57 
59 
57 

62 

63 

63 

65 

68 

69 

71 


4 






















LIST OF FIGURES (Continued) 


NO. PAGE 

27. Semicircular Storage Adapted to Locations near Power House or Coaling 

Stations.72 

28. Locomotive Crane Reclaiming Coal and Dumping into Bins above Rail¬ 

road Tracks.73 

29. L. and N. R. R. Type of Mechanical Coaling Station.75 

30. Towers Employed in Handling Coal, Western Coal and Dock Company, 

Waukegan, Illinois.77 

31. Traveling Tower or Direct Unloader.77 

32. Hunt System of Handling Coal. . 78 

33. Bridge Gantry Crane with Electrically Operated Man Trolley ... 78 

34. Coal Handling Plant of the Reiss Coal Company at Superior, Wisconsin. 79 

35. Man Trolley Coal Storage Bridges of the Indiana Steel Company . . 79 

36. Belt Conveyor Type of Bridge of the Inland Steel Company ... 80 

37. Movable Bridge with Side Dump Cars.80 

38. Traveling Bridges of the Clarkson Coal and Dock Company, Duluth, 

Minn.83 

39. Parallel Track Storage Yard for a Locomotive Coaling Station ... 87 

40. Layout of Storage Yard for Locomotive Coal Station.87 

41. Movable Screening Plant of Berwind Coal Company.83 

42. Swivel Bridge Designed for Semicircular Pile.89 

43. Pivoted Bridge of the Milwaukee Coke and Gas Company .... 91 

44. View looking toward Pivoted End Bridge of the Milwaukee Coke and 

Gas Company.92 

45. Bulkhead at the Storage Plant of the Milwaukee Coke and Gas Company 93 

• * 

46. View showing Construction of the Bulkhead at the Plant of the Mil¬ 

waukee Coke and Gas Company.93 

47. Hulett Unloaders of the Canadian Pacific Railway at Fort William, 

Ontario.94 

48. Reinforced Concrete Storage Bins of F. W. Stock and Sons, Hillsdale, 

Michigan, designed and built by Macdonald Engineering Company, 
Chicago.95 

49. View of the Under-water Storage Pit of the Western Electric Company 

at Hawthorne, Illinois.96 

50. View of the Under-water Storage Pit of the Western Electric Company 

at Hawthorne, Illinois.96 

51. Coal Storage Pit of the Illinois Traction Company at Mackinaw, Illinois 102 

52. Storage Pit of the New Kentucky Coal Company, Kankakee, Illinois . 97 

53. Concrete Storage Pit of the Indianapolis Light and Heat Company . 97 

54. Storage Pit of the Metropolitan Water District of Omaha .... 98 


5 



















LIST OF FIGURES (Continued) 


NO. 

55 . Storage Pit and Bridge of the Western Clock Works. 

56. Apparatus Used to Determine the Extent of Breakage in Coal Caused 

by Dropping in Tests at the University of Illinois. 

57. Chart showing Extent of Breakage in a 50-pound Sample of S''reened 

Lump Coal (over 2 inches) Dropped from a Height of Six Feet in Per 
Cent of Original Sample. 

58. Typical Storage Yard of the Consumers’ Company, Chicago .... 

59. Twenty-five-Thousand-Ton Pile of Run of Mine Coal stored by the Union 

Light and Power Company, St. Louis, Missouri . . . 

60. Suggested System of Storage for a Mine in a Hilly Country .... 

61. Suggested System of Storage for Screenings at the Tipple. 

62. Coal Pile of the C. C. C. and St. L. R. R. near Hillary, Illinois . 

63. Another View of the Burning Coal Pile of the C. C. C. and St. L. R. R. 

near Hillary, Illinois, in the Summer of 1917. 


LIST OF TABLES 

NO. 

1. Quantity of Coal and Coke Used in Chicago during 1912. 

2. Days of Active Operation of Mines for Seventeen Years. 

3. Horizontal Pressure Exerted by Bituminous Coal against Vertical Retain¬ 

ing Walls per Foot of Length. 

4. Capacity of Circular Crane Storage (Link-Belt Company). 

5. Decrease in Heating Value (B. t. u.) of Illinois Coals. 

6. Increase in Fine Material after One and One-Half and Six Years of Storage 

7. Temperature of Coal Stored at Hillary, Illinois, by the C. C. C. & St. L. 

R. R. 


PAGE 

99 

125 


123 

164 

169 

177 

177 

185 

186 


PAGE 

20 

25 

50 

70 

108 

121 


187 






THE STORAGE OF BITUMINOUS COAL 


I. Introduction 

1. Preliminary Statement .—The coal shortage during the win¬ 
ter of 1917-18, and the resulting inconvenience, suffering, and 
industrial loss have emphasized both the importance and the com¬ 
plexity of the problem of guarding against a recurrence of the situa¬ 
tion. The problem is one which concerns not only the Federal Fuel 
Administration and the State Councils of Defense, but the individual 
industry and even the individual household. It is generally recog¬ 
nized that perhaps the most important factor contributing to the 
shortage of fuel has been the inability of the transportation system 
to handle the heavy winter fuel tonnage in addition to the abnormally 
large tonnage from other sources. It is evident, therefore, that if 
large quantities of coal can be stored at or near the point of use 
during those seasons when consumption is lightest and when the 
railroads are best able to handle the traffic, an important step ^dll 
have been taken in the solution of the problem. 

It is the purpose of this circular to present a review of modern 
practice governing the storage of coal and a statement of the facts 
which have developed in the experience of those who have success¬ 
fully or otherwise undertaken to store coal. The discussion is confined 
largely to bituminous coal which has given so much trouble owing 
to its tendency toward spontaneous combustion while stored, and to 
storage systems and mechanical devices. 

The storage of coal should be regarded not merely as a war meas¬ 
ure, but as part of the solution of the general coal problem. Storage 
of coal will do much to help in stabilizing an industry of fundamental 
importance by permitting mining operations to proceed throughout 
the year at a fairly uniform rate, and it will serve in a large measure 
as insurance against the losses accompanying a shortage to the fuel 
consuming industries. 

At the present time large quantities of coal are stored by dis¬ 
tributing companies on the Great Lakes and along the seaboard; 
fairly large quantities by coke, steel, gas, and power plants, by a 


7 



8 


ILLINOIS ENGINEERING EXPERIMENT STATION 


few wholesalers situated at a distance from the coal fields, and by 
many railroads; smaller quantities by small power plants and a few 
mining companies; and still smaller quantities by the ordinary house¬ 
holder. 

Interest in the subject of coal storage is rapidly increasing, a 
fact which is shown by the large number of letters received by the 
Department of Mining Engineering and the Engineering Experiment 
Station of the University of Illinois, and the amount of coal stored 
will no doubt increase as the feasibility and advantages of storage 
become more fully understood. 

The data presented have been compiled from the record of cor¬ 
respondence and interviews with a large number of persons in charge 
of storage yards, with the manufacturers of storage machinery, and 
with the officials of various coal associations. Visits have been made 
to a number of plants in Illinois and the adjoining states, and the 
literature of the subject has been freety consulted. It has thus been 
possible to compile within a comparatively short period the results 
of the experience of those who have been storing coal. In order to 
reach as many different sources of information as possible a ques¬ 
tionnaire was prepared and sent to about 175 individuals and cor¬ 
porations,* Groups of industries were selected in order that as many 
different points of view as possible might be presented. These groups 
included the zinc smelting companies in Illinois, the steel companies 
and the by-product coke companies of Illinois, Indiana, Wisconsin, 
and Missouri, large public service corporations, many of the steam 
and electric railroads, representative wholesale and retail dealers 
suggested by I. L. Eunyan, Secretary of the Illinois and Wisconsin 
Coal Dealers Association, the secretaries of all the coal operators’ 
associations in the United States, the dock owners about the Great 
Lakes, large manufacturers, and other users of coal. The fire depart¬ 
ments of a large number of cities w,ere also consulted. The careful 
and prompt attention given to the requests for information indicated 
a wide-spread interest in the subject, and the responses were most 
gratifying. 

The theoretical considerations connected with the spontaneous 
combustion of coal and the other phenomena incident to coal storage 
have been investigated by S. W. Parr, H. C. Porter, F. K. Ovitz, and 
J. B. Porter, and the results of much experimental work by these and 


* The form of this questionnaire is shown on j). 130. 






THE STORAGE OF BITUMINOUS COAL 


9 


other investigators are contained in the publications of the Engineer¬ 
ing Experiment Station of the University of Illinois, the U. S. Bureau 
of Mines, and the Canadian Department of Mines. There is pre¬ 
sented here only such a summary of these results as is necessary for 
a consideration of the engineering features of coal storage. 

The International Railway Fuel Association as the result of a 
paper on coal storage by its former secretary, C. G. Hall,* has car¬ 
ried on a most valuable work through its Committees on Coal Storage 
and Fuel Stations. The Committee on Prime Movers of the National 
Electric Light Association also presented a useful report,! in 1917, 
on the subject of coal storage. 

This circular represents merely a report of progress in an in¬ 
vestigation which it is hoped will be continued. Its purpose is to 
bring to the attention of those who are considering the advisability 
and possibility of insuring themselves a regular fuel supply as much 
in the way of useful and helpful suggestions as possible. Additional 
data or suggestions from those into whose hands the circular may 
fall will be welcomed by the author. 

2. Acknowledgments. — Grateful acknowledgment is made of 
lielp accorded by Professor S. W. Parr, Professor of Applied Chem¬ 
istry, University of Illinois, and Professor E. A. Holbrook, Super¬ 
vising Mining Engineer, IMetallurgist and Superintendent of U. S. 

Bureau of Mines, Urbana, Illinois, and formerly Professor of Mineral 
Preparation and Utilization at the University of Illinois, who have 
cooperated most heartily and have contributed data gathered in 
connection with their own investigations of the subject. 

Wherever it has been possible, full credit has been given for 
definite data used and for direct quotations from other publications, 
but it has been impossible to do so in all cases, and many of the 
opinions expressed and the suggestions made represent composite 
ideas based upon a large amount of correspondence and much read¬ 
ing. 

3. Summary of Conclusions. — Based upon the facts and in¬ 
formation hereinafter presented certain definite statements are justi¬ 
fied regarding the reasons for storing coal, the kinds and sizes of coal 
to be stored, the methods of piling, and other factors entering into 


* “Storage of Coal: Its Feasibility and Advantages to Producer, Carrier and Con¬ 
sumer,” Proceedings, International Railway Fuel Association, Vol. VI, pp. 109-130, 1914. 

t Published by the National Electric Light Association, New York City. 



10 


ILLINOIS ENGINEERING EXPERIMENT STATION 


the problem of successful coal storage. These represent very largely 
a digest of opinions expressed by many persons who have had ex¬ 
perience in storing coal and, it is believed, constitute a comprehensive 
statement of the present knowledge of safe coal storage practice. 
These conclusions are presented as follows: 

(1) It is practical and advantageous to store coal not only dur¬ 
ing war times but also under normal conditions, at the mine, near the 
point at which it is to be used, or at some intermediate point. If 
possible, it should be stored near the point of consumption to avoid 
rehandling and the resultant breakage. 

The reasons for storing coal are: 

(a) To insure the fuel consumer a supply of coal at all times. 

(b) To take advantage of low freight rates, or of low prices 
for coal at certain seasons of the year. 

(c) To permit the railroads to utilize their cars and equip¬ 
ment to the best advantage. 

(d) To maintain a uniform rate of production at the mines. 

(2) Kinds and sizes of coal which may be safely stored: 

(a) Although it is undoubtedly true that some coals may 
be stored with greater safety than others, the danger from spon¬ 
taneous combusion is due more to improper preparation and pil¬ 
ing of coal than to the kind of coal stored. 

(b) Most varieties of bituminous coal may be safely stored 
if of proper size and if free from fine coal and dust. The coal 
must be handled in such manner as to prevent excessive breakage 
and the consequent production of much fine coal and dust when 
being placed in storage, because spontaneous combustion is due 
mainly to the oxidation of the coal surface. The danger of spon¬ 
taneous combustion in storing coal is very greatly reduced, if not 
entirely eliminated, by storing only lump coal from which the 
dust and fine coal have been removed. Of two coals, the one which 
is least friable should be chosen for storage purposes because less 
dust and fine coal will be produced in its handling. All varieties 
of bituminous coal can be stored under water, since water excludes 
the air and prevents spontaneous combustion. 

(c) Fine coal or slack has sometimes been safely stored in 
cases in which air has been excluded from the interior of the 


THE STORAGE OF BITUMINOUS COAL 


11 


pile. Exclusion of air from the interior may be accomplished 
(1) by a closely sealed wall built around the pile or (2) by close 
packing of the fine coal. Any pile of slack requires careful watch¬ 
ing to detect evidences of heating and means should be provided 
for moving the coal promptly if heat develops. The only abso¬ 
lutely safe way to store slack or fine coal is under water. 

(d) Many varieties of mine run coal cannot be stored 
safely because of the presence of fine coal and dust mixed with 
the lumps. 

(e) Coal exposed to the air for some time may become 
“seasoned” and thus may be less liable to spontaneous com¬ 
bustion because of the oxidation of the surfaces of the lumps of 
coal, but opinions are by no means unanimous on this point. 

(f) It is believed by many that damp coal or coal stored 
on a damp base is peculiarly liable to spontaneous combustion, 
but the evidence on this point is by no means conclusive. It is 
safer not to dampen the coal when or after it is placed in storage. 

(3) The effect of sulphur on spontaneous combustion: 

It has been shown by experimentation that the sulphur con¬ 
tained in coal in the form of pyrites is not the chief source of spon¬ 
taneous combustion, as was formerly supposed, but the oxidation of the 
sulphur in the coal may assist in breaking up the lumps of coal and 
thus may increase the amount of fine coal which is particularly liable to 
rapid oxidation. Even this opinion is not unanimously endorsed. In 
spite of experimental data showing that sulphur is not the determin¬ 
ing element in spontaneous combustion, the opinion is wide-spread 
that, if possible, it is w^ell for storage purposes to choose a coal with 
a low sulphur content. 

(4) Method of piling coal: 

(a) To prevent spontaneous combustion, coal should be so 
piled that air may circulate freely through it and thus may carry 
off the heat due to oxidation of the carbon, or it should be so 
closely packed that air cannot enter the pile and oxidize the fine 
coal. 

(b) Stratification or segregation of fine and lump coal 
should be avoided, since an open stratum of coarse lumps of coal 
provides a passage through which air may enter and come in 


12 


ILLINOIS ENGINEERING EXPERIMENT STATION 


contact with the fine coal, thus oxidizing it and starting com¬ 
bustion. 

(c) If space permits, low piles are preferable since in low 
piles the coal is more fully exposed to the air and is better cooled 
than in high piles and in case of heating it can be more readily 
and quickly moved. A disadvantage of high piles lies in the 
greater difficulty of moving the coal quickly, if necessary. The 
idea that a high pile causes heating at the bottom is erroneous, 
since as many fires take place near the top as near the bottom, 
and as many near the outside as near the interior of the pile. 
If possible, the coal should be divided by alleyways so as to fa¬ 
cilitate rapid loading out of the coal in case of necessity, and 
so that an entire coal pile may not be endangered by a local fire. 

(d) Much of the attempted ventilation of coal piles has 
been inadequately done through the use of only an occasional 
ventilation pipe, which has been not much more than a place 
in which to insert a thermometer. The practice of placing ven¬ 
tilating pipes closely together has been used in Canada and is re¬ 
ported to be effective. 

(e) Water is an effective agent in quenching fire in a coal 
pile only if it can be applied in sufficient quantities to extinguish 
the fire and to cool the mass. A small quantity of water is not effec¬ 
tive. Unless there is an ample supply of water thoroughly to 
quench the fire and to cool the pile, it is very dangerous to add 
any water to a coal pile. 

(f) Coals of different varieties should if possible not be 
mixed in storage, for the coal possessing the greatest tendency 
toward spontaneous combustion may jeopardize the safety of 
other varieties not so liable to spontaneous combustion. 

(5) The effects of storage upon the properties of coal: 

(a) The heating value of coal as expressed in B. t. u. is de¬ 
creased very little by storage, but the opinion is wide-spread 
that storage coal burns less freely than fresh coal. Experiments 
indicate that much of this deficiency may be overcome by keep¬ 
ing a thinner bed on the grate and by regulating the draft. 

(b) The coking properties of most coals seem to decrease 
as a result of storage, but coals vary greatly in this respect. 


THE STORAGE OF BITUMINOUS COAL 


13 


(c) The deterioration of coal stored under water is negli¬ 
gible, and such coal absorbs very little extra moisture. If only 
part of a coal pile is submerged, the part exposed to the air is 
still liable to spontaneous combustion. 

(6) Additional precautions: 

(a) The best preventive of loss in coal storage is regularly 
to inspect the pile. If the temperature reaches 150 degrees F., 
the pile should be carefully watched and if the temperature rises 
to 175 or 180 degrees F. the coal should be removed as promptly 
as possible. The coal should be thoroughly cooled before being 
replaced in storage. 

(b) Storage appliances and arrangements should be so 
designed as to make it possible to remove the coal quickly if 
necessary, and coal should not be stored in large piles unless 
provision is made for loading it out quickly. 

(c) Pieces of wood, greasy waste, or other easily combustible 
material mixed in a coal pile may form a starting point for a 
fire, and every effort should be made to keep such material from 
the coal as it is being placed in storage. 

(d) Tt is important that coal in storage should not be sub¬ 
jected to such external sources of heat as steam pipes, because the 
susceptibility of coal to spontaneous combustion increases rapidly 
as the temperature rises. 

Warning : Special emphasis is laid upon the fact that safety in 
the storage of coal depends upon a very careful and thorough consid¬ 
eration of and attentimv to the details referred to in the foregoing. 
Lack of attention to these details and lack of care in handling will in 
many cases result in losses due to dangerous fires. Do not undertake 
to store coal until you are sure you know how to do it properly and^ 
safely. 


14 


ILLINOIS ENGINEERING EXPERIMENT STATION 


11. Reasons for Storing Coal 

4. Present Mming Conditions .—An ideal condition with regard 
to the production, distribution, and utilization of coal would permit 
the steady operation of mines without requiring the storage of large 
quantities of coal. There would be just enough mines to produce 
the coal required with only a suitable excess as a safety factor ; these 
mines would be operated steadily for from 300 to 310 days per year 
and the coal would be taken away as rapidly as produced and de¬ 
livered to the consumers as needed. This ideal condition is, however, 
far from being fulfilled. The actual condition is that an excessive 
number of mines is being operated, variously estimated as capable 
of producing from 50 to 150 per cent above the normal demands of 
the market, that these mines are irregularly worked for a total of 
only about 200 days per year producing much less during the spring 
and summer than during the fall and winter, and that the railroads 
have not adequate equipment to handle all the coal if all the mines 
were operated full time. 

The storage of coal will not increase the amount used, and it 
may result in closing down unprofitable mines and in discouraging 
the opening of new mines until the readjusted demand may justify 
the operation of such mines on a profitable basis. Storage should 
make possible fairly uniform operation throughout the year and 
should help make the coal industry stable instead of intermittent and 
uncertain as at present. More nearly uniform operation of the mines 
and a greater number of days of work per year are necessary if coal 
is to be produced at a minimum cost and if the miners are to be kept 
satisfied, for no body of workmen can be satisfied with the irregular 
working conditions which have prevailed for many years in the coal 
mines of the United States. Regular operation also means the more 
systematic removal of the coal, greater extraction, and greater con¬ 
servation of a natural resource. 

The variation in the price of screenings has frequently been very 
great. In the summer, when the demand for coal has^een small 
and the demand for fine sizes relatively large, screenings have com¬ 
manded a price of one dollar or more per ton, while in the fall and 
early winter, when the demand for coal is greatest, the production 
of screenings has sometimes been so much in excess of the immediate 


THE STORAGE OF BITUMINOUS COAL 


15 


demand as to reduce the price at the mine to as little as ten cents 
per ton. 

The variations in prices for different sizes of coal, as given by 
Prof. E. A. Holbrook,* show the advisability, from the standpoint 
of the buyer, of stocking coal to secure the advantage of lower prices 
during certain seasons. The general or extensive storage of coal 
should equalize these widely varying prices. 

5. Benefits of Storage .—The reports of the Coal Storage Com¬ 
mittee of the International Railway Fuel Association have shown that 
transportation lines should store coal, first, to assure a continuous 
supply of fuel for railroad operation at times when the supply from 
the mines may be cut off by fioods, storms, labor disturbances, or other 
causes, and secondly, to avoid the necessity of providing the excessive 
equipment of locomotives and coal cars which are needed if all the fuel 
demands of the winter season must be met during that season. This 
excessive equipment is a non-productive investment during a part of 
the year. 

Hallf says: 

‘ ‘ The storage of coal in the summer months will enable the carriers to move 
a percentage of the tonnage during that season, which they are now called upon 
to move during sixty to eighty days of each fall and early winter, and during 
which period no railroad in this country now has, or ever can afford to have suffi¬ 
cient power and cars to serve the mines and move the coal to accord with the 
demand. To do this, we will say five of the large coal moving roads of Illinois 
and Indiana would each have to buy fifty new locomotives and six thousand new 
coal cars: 

A total of 250 locomotives at $25,000.00 .$6,250,000 

A total of 30,000 cars at 800.00 . 24,000,000 

Total Investment of.$30,250,000 

the annual interest on which, at five per cent, would amount to $1,512,500, and a 
greater percentage of such cars and power would be idle eight months of the 
year. 

“This is only a small portion of the total investment that even this small 
group of railroads would have to make in order to handle the coal as the con¬ 
sumers now demand, as the expense of additional double and triple tracks and 
yard facilities would far exceed the cost of additional equipment and power. It 
is therefore very apparent that the carriers would have to spend so much money 
to provide 100 per cent service during the short abnormal offerings of coal that 

*“Dry Preparation of Bituminous Coal at Illinois Mines.” Univ. of Ill. Eng. Exp. 
Sta., Bui. No. 88. 1916. 

t Op. Cit., pp. 110-111. 





16 


ILLINOIS ENGINEERING EXPERIMENT STATION 


a substantial increase in freight rates would be the inevitable result, which of 
course would mean an increase in the ultimate delivered cost of the coal. Thus 
the consumers would not only be called upon to pay the interest on an excessive 
amount of capital invested in mines but would also have to carry the burden of 
an excessive investment in equipment and facilities on the part of the carriers. ’ ’ 

Between May 15 and July 15, 1914, the railroads had a surplus 
of 95,564 coal cars, representing an investment of $105,120,400. This 
amount of money would provide extensive storage facilities which 
would probably have a much longer life, and which would cost less 
for maintenance and depreciation than the surplus of coal cars. In 
the case of the railroads, one of the greatest advantages of storage 
lies in the opportunity it affords for moving railroad coal, which 
is not a revenue producing element, at a time when revenue produc¬ 
ing freight shipments are least. Railroads need storage to control 
traffic, and the coal operators need it to regulate production. 

Storage assures the wholesale and retail distributors of coal a 
supply in times of failure of railroads and of mines to furnish the 
regular daily supply owing to strikes and transportation disturbances. 
It permits distributors to take advantage of low freight rates, par¬ 
ticularly through the use of water transportation in the summer 
time, and possibly also of lower prices of coal at the mines during 
slack mining time. 

Hall* reached the following conclusions regarding coal storage: 

^ ‘ The storage of bituminous coal can only be made feasible by the producer, 
carrier and consumer cooperating closely to carry on the work in a systematic and 
economical manner. 

‘‘One million dollars spent by producers for storage facilities will afford 
more relief to the coal industry than five millions spent in the development of 
new mines. 

“One million dollars invested in storage facilities by railroads would go 
further toward relieving operating tangles and preventing car shortage than 
three million invested in cars and locomotives. 

“The purchase of coal by the industrial and domestic consumers, during the 
dull periods, will result in a saving of a very high per cent on the investment. ’ ’ 

The reasons for storing may be summarized as follows: 

(1) To assure the consumer an adequate supply which pro¬ 
tects him against strikes, other labor disturbances, and uncertain 

railroad deliveries. 


* Op. Cit„ p. 130. 



THE STORAGE OF BITUMINOUS COAL 


17 


(2) To take advantage of water transportation and low 
freight rates. 

(3) To secure the advantages of low prices. 

(4) To equalize the prices on the different sizes of coal. 

(5) To avoid the maintenance by the railroads of equip* 
ment which is used for only part of the year. 

(6) To maintain a uniform rate of production at the mines 









18 


ILLINOIS ENGINEERING EXPERIMENT STATION 


III. Places of Storage for Different Purposes 

6. Storage Near the Point of Consumption. —The place of storage 
should be near the point at which the coal is to be used, not only 
to assure a constant supply to the user, but to avoid the extra cost 
and extra breakage incident to each rehandling and to utilize trans¬ 
portation equipment to the best advantage. 

HalP says: 

‘ ‘ While unquestionably the best and most economical results can be obtained 
by moving the coal to final destination before storing, however, it may be desir¬ 
able and necessary to establish storage yards at principal distributing centers 
such as Chicago, Peoria, St. Paul, and Omaha, and in doing this the cooperation 
of producers and carriers will be essential. In fact, it would probably be feasible 
and desirable for the producers to control the storage companies. 

‘‘These central storage yards should have a capacity of 100,000 to 500,000 
tons, a screening plant to be installed in conjunction with the yard.’’ 

• 7. Storage for Domestic Use and for Small Power Plants. —The 
domestic consumer does not always realize that if his winter supply 
of coal is delivered in October or November, when he begins to use 
it, or in small amounts throughout the winter, he is contributing to 
the car shortage and is helping to make necessary the maintenance 
of more mines than the actual yearly consumption will justify. The 
householder should realize that there is no other item in his living 
expenses which will pay as large a return on the investment as to lay 
in a supply of coal in May or June, when it may usually be procured 
from fifty eents to one dollar per ton cheaper than in October or 
November. 

Although an increase in domestic storage during the summer is 
one of the simplest ways of helping to solve the storage problem, 
many householders canUot afford to pay their annual coal bill in a 
lump sum. Knowing this, retailers often ask on the basis of deferred 
or monthly payments as much as twenty-five cents a ton more than 
the cash price. The plan of making a definite reduction in price 
in the spring might be more generally tried. In the anthracite region 
of Pennsylvania, for instance, a reduction of fifty cents per ton in 
the retail price in usually made April 1 and an increase of ten cents 
per month is added until by September 1 this reduction has been 


* Op. Cit., p. 113. 



THE STORAGE OP BITUMINOUS COAL 


19 


made up. Some such stimulus is justifiable to help keep the mines 
operating more steadily during the summer months and to allow the 
railroads to transport the coal when the car supply is available. Sys¬ 
tematic advertising campaigns calling attention to the advantages of 
buying during the summer have been carried on by a number of coal 
dealers, notably in Springfield, Illinois, where full page advertise¬ 
ments have appeared in the daily and Sunday papers.' 

In small cities like Urbana and Champaign where the popula¬ 
tion is from 25,000 to 30,000 the amount of coal used per year is from 
75,000 to 100,000 tons. The dealers estimate that an ordinary eight 
room house requires from fifteen to twenty tons per year, and that 
seventy per cent of this amount are stored in basements during the 
summer months, when the price is about fifty cents per ton less than 
in winter. In towns which have a large industrial population the 
percentage stored during the summer is less and the sales are dis¬ 
tributed throughout the year. In towns where the local supply comes 
from neighboring mines, the incentive for storage is not so great 
since there is not often any variation in price and no likelihood of a 
scarcity. 

Hall"*^ says: 

‘'If consumers are asked to cooperate with producers and carriers to the 
extent of storing some coal during the spring or summer they will expect to be 
shown wherein they will be benefited, and this also holds true in the case of dealers 
or jobbers who may plan to go into the storage proposition on a large scale. 

‘ ‘ The producer has in the past, and will in the future unquestionably make 
sufficient price concessions during the spring and summer months to cause that 
to be an attractive feature of storage. 

‘ ‘ The carriers should also offer inducements in the nature of freight rates 
with ‘ storage in transit ’ privileges and should make lower rates during the months 
that is to the advantages of all interests to store coal. 

‘ ‘ The total operating expenses of the railroads moving the Illinois and 
Indiana coal to Chicago and the adjacent territory north and west show an in¬ 
crease of 31 per cent in proportion to gross earnings in a severe winter month 
as compared with a spring or summer month. It is therefore entirely fair, and 
in fact a sound business proposition for these carriers to make a corresponding 
variation in freight rates. For example the present rate to a given point is $1.00 
per ton—why should not a rate of 85 cents be made for the months of April, May, 
and June; 95 cents for July, August and September, and $1.10 for the remaining 

months of the year? ’’ 

- ^ 

In this connection Coal Tariff 2338 of the Illinois Central Rail¬ 
road, issued December 6, 1915, is of interest: 


* Op. Oit., pp. 112-113. 



20 iLLINOiS ENGINEERING EXPERIMENT STATION 

‘ ‘ Storage in transit at Kankakee, Ill., of Bituminous Coal, C. L. 

^ ‘ Bituminous Coal, carloads, originating at Mines and Stations on Illinois 
Central Railroad and connections in Illinois, and destined to Chicago, Illinois, 
may be unloaded and stored in transit at Kankakee, Illinois. 

‘‘Shipments will be way-billed to Chicago, Ill., with notation on way-bill 
‘ To be unloaded and stored at Kankakee, Ill. ’ 

“The through rate, lawfully on file with the Illinois Public Utilities Com¬ 
mission, in effect on the date of forwarding from original point of shipment to 
Chicago, Ill., plus $2.00 per car for reconsigning and extra service, will be pro¬ 
tected when shipments are reloaded and forwarded to Chicago, Ill. 

“On reshipments of storage coal the deduction for moisture, on shipments of 
screenings, from the actual net weight as ascertained on track scales at Kankakee, 
Ill., will be five (5) per cent. 

“Agent at Kankakee, Ill., to show gross, tare and net weight, and deduction 
for moisture on face of way-bill. 

“No deduction will be allowed if weighed en route or at destination. 

‘ ‘ If the shipments are not forwarded from Kankakee, Ill., within six months 
from the date they were forwarded from original point of shipments, through 
rate, lawfully on file with the Illinois Public Utilities Commission, in effect from 
the original point of shipment to Chicago, Ill., will be collected at that time. 

“Owners will be required to unload and reload the coal. 

“Shipments will be subject to Car Demurrage Rules lawfully on file with 
the Illinois Public Utilities Commission. 

“Note:—Applicable only on trafidc having point of origin, destination and 
entire transportation within the State of Illinois. “ . 

In this connection, it is interesting to note the distribution among 
different classes of service of coal used in the city of Chicago.* A 


Table 1 

Quantity of Coal and Coke used in Chicago during 1912 


Service 

Tons 

Per Cent 

(l) Steam Locomotives. 

2,815,400 

13.27 

(2) Steam Vessels. 

(3) High Pressure Steam Stationary Power and Heating Plants; 

92,368 

0.44 

Including public service corporations, municipal, steam railroads, 
office buildings, hotels, schools, power plants, or boiler plants. . . 

9,147,344 

43.13 

(4) Low Pressure Steam and Other Stationary Heating Plants; 



Including large and small buildings, large and small apartments 
and residences. 

4,646,910 

21.91 

(5) Gas and Coke Plants; 


Excluding boiler power plants. 

(6) Furnaces for Metallurgical, Manufacturing and Other Processes; 

253,867 

1.20 

Including steel plants, foundries, forges and allied processes; 
brick, pottery and allied processes, and miscellaneous manu¬ 
facturing, rendering and other processes, excluding boiler power 
plants. 

4,253,007 

20.05 

Totals. 

21,208,886 

100.00 


* Report of the Chicago Association of Commerce Committee of Investigation on Smoke 
Abatement and Electrification of Railway Terminals, p. 110, 1915. 















THE STORAGE OP BITUMINOUS COAL 


21 


study of this table will indicate the points of attack in a campaign 
to increase the amounts of coal to be kept in storage. 

The average retailer is in much the same condition as the house¬ 
holder, to the extent that he does business on limited capital and 
cannot afford to lay in a heavy stock, even if he has the required space 
and facilities. According to The Black Diamond,"^ there is one retail 
dealer in the United States for every two thousand inhabitants, which 
means that the average retailer handles only about 7500 tons per 
year. Since there is usually in every town some corporation which 
handles a large proportion of the retail coal business the average 
dealer’s business will probably amount to much less than 7500 tons. 
There are at least twenty coal dealers in Champaign and Urbana for 
a population of about 25,000. Since the consumption in these towns 
is probably not over 100,000 tons per year, the average sales per deal¬ 
er are not more than 5,000 tons. The ordinary retail dealer cannot af¬ 
ford to put much money into costly storage appliances which add 
greatly to his overhead charges, nor to buy the land necessary to store 
great quantities. The comparatively small amounts stored are kept 
usually in small bins under cover and are stored for only a short 
time. 

One way out of the difficulty would be to establish cooperative 
storage plants which could serve as common storage facilities for a 
number of dealers. Such cooperative schemes have not, however, 
been generally successful. In Rock Island, Illinois, a company has 
built a number of storage bins which are rented. In a large city, 
storage facilities for any considerable quantity of coal would usually 
have to be located in the outlying districts to keep the rental cost 
for the land within reasonable limits. A ton of coal occupies about 
forty cubic feet; hence to store one thousand tons in a pile ten feet 
high would require a space sixty-three feet square. 

Large office buildings, hotels, and stores are the largest users of 
coal per foot of floor area. In Chicago the amount used per building, 
according to The Black Diamond, varies from seven to sixty tons 
per day. 

For large buildings two kinds of storage must be provided, 
namely, the current daily working storage and the reserve or emer¬ 
gency storage to tide over strikes, bad weather conditions, trans¬ 
portation difficulties, and other contingencies. Provision for the 


* February 3. 1917. 





22 


ILLINOIS ENGINEERING EXPERIMENT STATION 


storing of coal for the current supply is a necessity and need scarcely 
be considered in connection with the broader phases of the question, 
since it is a matter of architectural design and depends largely upon 
the space available in a given building. If a building requires 40 
tons per day, a storage space of 1600 cubic feet is necessary for a 
day’s supply and a room approximately 30 by 30 by 10 feet for a 
week’s supply. According to The Black Diamond* this storage 
space in the loop district of Chicago is worth a rental of three dollars 
per square foot per annum for power purposes. The Continental and 
Commercial National Bank uses this space for its vaults, and their 
rental value is about eight dollars per square foot. That makes its 
value two and two-thirds times the value of the same space for power 
generating purposes. The Rector building in Chicago rents its base¬ 
ment to a restaurant for six dollars per square foot. This fact shows 
that the basement is worth almost as much as the ground floor space, 
and more than twice as much as the office space of the upper stories. 
Such buildings must have a regular daily supply, and they must use 
their own space at a high rental loss, or some provision for storage 
must be made by the wholesalers, or by the railroads. Local storage 
of large quantities of coal for such a district as the loop in Chicago 
is, therefore, impracticable without an unreasonable increase in the 
fuel bill, and some other solution of this part of the problem must 
be worked out. 

Public utilities companies, owing to the constantly increasing 
governmental supervision which requires uninterrupted service, and 
the by-product coke companies, the steel companies, and other in¬ 
dustries which must run continuously must necessarily regard stor¬ 
age as a matter of necessity, unless they are situated near the mines. 
Many of the zinc smelters in Illinois, although in mining towns, have 
ample storage facilities. 

8. Storage hy Railroads .—The railroads are interested in stor¬ 
age both because they are the largest users of coal and because they 
are interested in utilizing their coal carrying equipment to the best 
advantage. 

According to the United States Geological Survey, the railroads 
of the United States used, in 1916, 136,000,000 tons of bituminous 
coal (27 per cent of the total production), 6,735,000 tons of anthra- 


* Op. Cit. 



THE STORAGE OF BITUMINOUS COAL 


23 


cite (7.1 per cent of the production), and 22,950 tons of coke. The 
railroad consumption of bituminous coal in 1916 showed an increase 
of 14,000,000 tons, or 11.5 per cent over 1915. The quantity of bi¬ 
tuminous coal used by the railroads in the eastern district increased 
from 56,500,000 to 62,700,000, or 11 per cent. The increase in the 
southern district was from 22,000,000 to 23,300,000 or 5.1 per cent, 
and in the western district, from 43,500,000 to 50,000,000, or 15 per 
cent. 

There is a difference of opinion concerning the place at which 
a railroad should store coal. Some recommend storage at the using 
point, i. e., at each coaling station, while others suggest some central 
point from which a number of coaling stations may be supplied. 
Even though the cost of providing storage facilities at each coaling 
station may he prohibitive at present, many advise that in locating 
coaling stations consideration be given to the possibility of subse¬ 
quently erecting storage facilities at such points. Some recommend 
a central storage plant for each division, so that each superintendent 
may be responsible for his own fuel supply. Others recommend only 
general terminal supply stations. The cost of installation and opera¬ 
tion of one large plant must be compared with that of a number of 
smaller ones, and the item of additional breakage must also be con¬ 
sidered. 

9. Storage at the Mine .—There is a wide diversity of opinion 
concerning the advisability of storing at the mine, many claiming 
that it is not desirable, since it neither increases the output nor helps 
the transportation problem. It is as logical economically for the 
producer of coal to store coal at the mine as it is for the manufacturer 
of cement to store cement at his plant. 

Storage near the point of consumption is, of course, the best 
method, but storage at the mine possesses such advantages as to war¬ 
rant its consideration. Even a small storage pile at the mine may 
permit the mine to begin running in the morning when railroad cars 
have not been delivered and when ordinarily the mine would not 
start owing to the uncertainty of a car supply later in the day. It 
may also often tide over periods of the day when additional cars are 
needed. During the early part of the week the car supply is usually 
good, but it falls off during the latter part, and storage should help 
to increase the regularity of running. 








24 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Carl Scholz* says: 

‘' Lump and egg coal should be stored at destination by railroads, industrial 
plants, and domestic users during the period from April to August. Screenings 
should be stored at mines by coal operators during the period from September 
to January.’^ 

By storing at the mine, the operators are fortified against fluctu¬ 
ations in demand. Occasionally an operator cannot increase his out¬ 
put rapidly owing to insufficient mine development; whereas if he 
has a stored supply upon which to draw, he may retain the business 
and at the same time proceed with the development until his capacity 
is increased to meet the extra demand. Suitable storage facilities 
at the mine will make possible more rapid working and better ex¬ 
traction. Storage will also help to equalize the difference in demand 
for different sizes, and will permit shipments to continue when the 
mine is shut down. Operating expenses at a mine, as with the rail¬ 
roads, are usually greatest in the winter and mining would, therefore, 
be more profitable if the mines could be worked steadily during the 
summer and spring months. 

E. A. McAuliffet has stated the advantages of storing as affecting 
labor conditions at the mine as follows: 

‘‘A shop man ordinarily receives some limited notice relative to short hours 
or reduction of force. Engine and trainmen have learned by experience that busi¬ 
ness falls off at certain seasons, but they know at the same time that they will 
be permitted to make a mileage at least reasonably commensurate with their 
domestic and their financial requirements; not so with the miner, with the fellow 
that digs the coal; he works to the extreme limit of his ability, or at least he 
has the opportunity to work to the limit of his ability, one week, when suddenly, 
without notice, due possibly to an unforeseen weather condition, business slumps 
and he gets one day or two days a week. In the meantime his operating expenses 
are running on just the same. I think that condition is very largely responsible 
for the unrest, for the dissatisfaction, that the mine worker labors under. That 
he does not take a greater interest in the affairs of his employer, in the per¬ 
manency of his vocation, I think is very largely due to the fact that he does not 
know what he is going to earn next week. When night comes he can sum up what 
he earned today, but he does not know what tomorrow holds in store for him. 
There is no business on earth subject to the tremendous and violent fluctuations 
that the production of coal is subject to. Today we demand the maximum, or if 
possible, more than the maximum output of all the mines; tomorrow we are 
quite indifferent to whether the operator sells his product or otherwise. The 
storage of coal, and the movement from the mines to the stock piles during these 
temporary depressed periods is the only same solution of that problem.’^ 


* Proceedings, International Railway Fuel Association, Vol. VII, p. 267, 1915. 
t Proceedings, International Railway Fuel Association, Vol. VI, p. 143, 1914. 



THE STORAGE OF BITUMINOUS COAL 


25 


The small number of working days at Illinois mines is shown by 
the following table, taken from the Illinois Coal Report. 


Table 2 

Days of Active Operation of Mines for Seventeen Years 


Year 

All Mines 

Shipping Mines 

Days 

Days 

1900 

183 

214 

1901 

174 

204 

1902 

179 

210 

1903 

192 

222 

1904 

198 

213 

1905 

174 

198 

1906 

172 

189 

1907 

184 

209 

1908 

171 • 

191 

1909 

168 

189 

1910 

171 

179 

1911 

165 

169 

1912 

160 

172 

1913 

170 

179 

1914 

162 

174 

1915 

158 

172 

1916 

163 

185 












26 


ILLINOIS ENGINEERING EXPERIMENT STATION 


IV. Coal Storage Practice 

10. Kinds and Sizes of Coal which may he Safely Stored. The 
opinion is current that the locality from which a coal comes determines 
its suitability for storage. One frequently hears such a remark as, 
‘‘Eastern coals (meaning those from Pennsylvania and West Vir¬ 
ginia) can be easily stored but Western coals (meaning those from 
Illinois and Indiana) cannot be since they are much more liable to 
spontaneous combustion. ’ ’ 

This statement is too general to fit the facts, because scientific 
research and the experience of those storing coal have shown that 
while there are undoubtedly inherent differences in coals which affect 
their liability to spontaneous combustion and to degradation, these 
differences are of less importance than the size of the coal and the 
way in which it is stored. The answers to the questionnaire (Ap¬ 
pendix II) indicate that almost any coal may be stored if it is prop¬ 
erly piled, and that almost any coal improperly stored will heat and 
may fire. 

The C. W. Hunt Company, of Staten Island, makes the following 
statement: 

‘‘Any coal of fair quality, both anthracite and bituminous, can be suc¬ 
cessfully stored for an indefinite length of time. There is a slight deterioration 
both chemical and physical, but this is not serious, provided the coal does not 
heat. Low grade bituminous coals are subject to heating and should not be stored 
above twenty feet in depth or for very long periods. Any storage of bituminous 
coal should be watched and if found to heat, should be moved. 

The Coal Storage Committee of the International Railway Fuel 
Association says with reference to storage by roads using Ohio, Penn¬ 
sylvania, and West Virginia coals: 

“The consensus of opinion in regard to the coals which may be screened 
without excessive breakage seems to be that the coal best adapted for storage is 
the three-fourths inch to the one and one-fourth inch lump. In the case of very 
friable coals such a separation of sizes is not practicable, for which reason they 
should be stored as run of mine and the storage piles so made as to minimize 
the danger attendant upon storing the coal of mixed sizes. ’ ’ * 

With reference to storage by the railways in the southeastern 
part of the United States the Committee says: 


* Proceedings, International Railway Fuel Association, Vol. VII, p, 260, 1915, 





THE STORAGE OF BITUMINOUS COAL 


27 


“It is agreed that lump coal of a firm quality, in order to resist powdering, 
is the best. The Central of Georgia Railway has been very successful in storing 
slack with a large percentage of nut. From the operators’ viewpoint, run of 
mine should be stored, as it leaves nothing on their hands. ’ ’ * 

With reference to southwestern railways the Committee says: 

“It is generally agreed that lump and nut coal with at least twenty-five per 
cent of slack removed is the best kind to store, that is, with the coals which will 
store without great danger of spontaneous combustion. 

‘ ‘ All who have tried to store Texas and part of the Arkansas coal have found 
that it is a failure on account of the liability to spontaneous combustion. 

“All other coals in the second territory—Oklahoma, Kansas, Missouri, and 
Northern Arkansas—can be stored and the loss in heating value and weight will 
be from two per cent to eight per cent.” t 

With reference to the railroads using Indiana, Illinois and Iowa 
coals the Committee says: 

‘ ‘ Lump and' egg coal should be stored at destination by railroads, industrial 
plants and domestic users during months April to August. Screenings should 
be stored at mines by coal operators during period September to January.” t 

W. L. Abbott, Chief Engineer of the Commonwealth Edison 
Company, Chicago, says: 

‘ ‘ The experience of the Commonwealth Edison Company after storing large 
amounts of all varieties of coal and particularly Illinois coals for a number of 
years may be summarized as follows: 

“Nearly any coal which has gone over a 1^-inch screen can be stored. 
Any size of coal with duff left in will heat. 

“Pea coal over one-half inch through three-fourths inches has been in stor¬ 
age for more than a year without heating. Coal with screenings removed has 
been kept in storage eight years without firing. 

‘ ‘ Heating usually occurs within three months after the coal has been stocked, 
and the tendency to heat decreases rapidly after that period. 

“Coal in storage piles shows no measurable loss of heating power, although 
weathering reduces the lumps on the outside of the piles to slack. 

“As insurance, cost of handling, etc., are the same for all grades of coal, 
regardless of heat value, it is more economical to store the better grades.” 

These statements are endorsed by others in Chicago who store 
large quantities of coal. 


* Ibid., p. 262. 
t Ibid., p. 264. 
$ Ibid., p. 267. 



28 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Hall * says: 

‘ ‘ On account of the cheaper prices which have prevailed on slack coal, the 
industrial concerns of the country have gradually been installing steam plants so 
equipped as to burn successfully that grade, resulting in a proportionately stronger 
demand for screenings, from April to August of each year, than any other size. 
This creates an ideal condition for storage as it enables the operator to supply 
the railroads, and other concerns that require it, sized coal such as nut and egg 
for current use and the large lumps for storage. There has been a surplus of 
egg as Tvell as lump coal during the spring and summer and this grade can also 
be stored to good advantage. The six-inch lump coal when stored and reloaded 
should be rescreened if any part of it is to be offered to the householder. Lump 
or egg when stored by the ultimate consumer and at the point of consumption 
can be recovered without appreciable degradation. 

‘‘During the fall and early winter, conditions are reversed and screenings 
become the unsalable size. This is the period that screenings should be stored 
at the mines. ’ ’ 

A. Bementf says: ‘Ht appeared that egg coal was the best size 
to put in storage and there has been an enormous tonnage of it stored 
in the open with complete success.” 

11. When Coal should he Stored .—To keep the mines running 
regularly and to relieve the congestion of the railroads, coal should 
be stored during the spring and summer. Coal which is moved to the 
storage point by water must be stored during the summer and early 
fall before the close of water navigation. 

From the standpoint of heating of the coal it is preferable to 
store during the cool days of the fall or winter, but many prefer to 
store during July and August, because then the coal is drier. Others 
prefer to store in May and June, because then labor is more easily 
obtained and more can be accomplished than during the hot summer. 

W. D. Langtry$ suggests the advisability of cooling steel coal 
cars before they are loaded and says: 

“One item which might prevent trouble in storing is the condition of rail¬ 
road cars in the summer when coal is loaded therein at the mines. We found 
that steel cars, for instance, would absorb the heat, to a great extent, from the 
sun, and if the coal was loaded into these cars this heat would be transmitted to 
the coal, thus giving it a good start for spontaneous combustion to continue. 
Some coals are more or less damp when freshly mined, and this and the heat are 
very good factors in giving the coal a good start. If the cars could be cooled in 
some way, by sprinkling them with a hose, when it is known that the coal is going 
in storage it might help somewhat.’’ 

* Proceedings, International Railway Fuel Association, Vol. VI, p. 125, 1914 

t The Black Diamond, April 7, 1917. 

t Personal Communication. 



THE STORAGE OP BITUMINOUS COAL 


29 


The following statement by F. W. Gray* is of interest with re¬ 
lation to the effects of the temperature at which coal is placed in 
storage: 

‘‘The most extensive storage yet undertaken was in the winter months of 
1913-1914, when 650,000 tons of coal were ‘banked’ by the Dominion Coal 
Company at their Glace Bay mines. The coal is lifted in the summer by steam 
shovels, rescreened and shipped. There has never yet been an actual fire in the 
round coal banks, although the first coal banked out must remain in the center of 
tlie pile for over six months before it is lifted. Heating sometimes takes place, 
but with proper methods this can be speedily checked and dissipated. The tem¬ 
perature of the air at the actual time of banking is an important consideration, as 
generally speaking the banked coal seems to remain at about the temperature 
which it had when placed in the bank. Tlie bulk of the coal placed on the ground 
is, of course, put there in cold or freezing weather. If a thermometer is lowered 
down a pipe into the interior of the bank it wdl usually register a temperature 
near to the freezing point, a fact that it is interesting to observe on a hot summer 
day, when the surface of the banked coal is quite warm to the hand. The coal 
is banked up to a height of from 40 to 46 feet, and over 300,000 tons have been 
stored in a continuous pile.” 

There is the greatest danger when coal is stored during the hot 
months, July and August, and the liability is greatly reduced if it is 
stored in May, June, September, or October. 

12. Storage Piles .—Storage piles are usually in the form of 
truncated cones or pyramids, the size depending mainly upon the 
appliances used for storing and reclaiming and upon the space avail¬ 
able. 

• The different sizes of coal are sometimes, if space permits, kept 
separate in storage, but often this plan is impracticable and the coal 
must be screened, if at all, as it is taken out of storage. 

If piled on the ground, the space should be clean, level and free 
from water or moisture. Many large piles are placed upon a board 
or concrete foundation. 

There is a wide diversity of opinion concerning the height of piles, 
and many think that piles should be not more than ten feet high. The 
opinion often expressed that the height of the pile is an important fac¬ 
tor affecting the extent to which coal at the bottom of the pile may be 
crushed does not seem to be substantiated by the facts. Tests made in 
the Materials Testing Laboratory of the University of Illinois on Illi¬ 
nois coal showed a maximum crushing strength of 2090 pounds per 

* “The Coal Fields and Coal Industry of Eastern Canada.” Canada Department of 
Mines, Bui. 14, pp. 11-12, 1917. 



30 


ILLINOIS ENGINEERING EXPERIMENT STATION 


square incli and a miniiiium of 1280 pounds. Similar tests on Con- 
nellsville coal showed a maximum strength of 3430 pounds per square 
inch and a minimum of 1310 pounds. Tests in England required 1.27 
tons per square inch to start cracking and 1.52 tons to crush the coal. 

Coal is seldom piled at present more than fifty feet high and at 
this height the pressure at the bottom of the pile would be only about 
fourteen pounds per square inch which is so small compared with the 
crushing strength as to be negligible. Any increase in fine material 
in high piles is probably due mainly to the handling of the coal, as, for 
example, dropping it from a considerable height or allowing it to roll 
down a long slope and thus produce breakage and abrasion. None of 
those who pile coal to a considerable height reports any crushing due 
to the height of the pile. 

Coal has been successfully stored in piles varying in height from 
six to sixty feet and it has also frequently fired in very low piles. The 
depth is not so important as the manner in which the coal is placed in 
storage and the facilities available for quickly removing it in case of 
firing. 

An examination of piles which have fired shows that the fires have 
started frequently near the top and sides and not at any great depth 
in the pile. A current of air in the pile too sluggish to carry off the 
heat, a piece of wood, or oily waste may furnish a starting place for 
fire. The theory has been advanced that the temperature of a current 
of air rising through a pile of coal in which oxidation is taking place 
receives sufficient heat from the oxidizing coal to increase the tendency 
to spontaneous combustion near the top. 

One objection to high piles lies in the difficulty of testing for 
heating. Low piles are advantageous because they can be easily 
watched and tested for a rise in temperature, and if necessary the coal 
can be removed quickly. 

In connection with experiments made on coal stored by the Ca¬ 
nadian Pacific Railway near Montreal, Canada, Prof. J. B. Porter* 
says: 

“It is interesting to note that the series of observations prove very clearly 
that the maximum heating was comparatively near the surface of the pile. As 
a matter of fact the hottest points were apparently not more than five or six feet 
from the surface, although the weather at the time was extremely severe. The 
common opinion of practical men in charge of coal storage is that fires usually 

* “Weathering of Coal.” An Investigation of the Coals of Canada, Extra Vol., p. 
164, 1915. 



THE STORAGE OF BITUMINOUS COAL 


31 


occur close to tlie bottom, but in this case it is almost certain that had the pile 
been left unventilated it would have ignited within a week or two at a depth 
of not over six feet, and in certain other cases which the author has observed, 
fires in large piles have actually originated at this depth. The probable reason is 
that in a pile of great extent and depth, the coal in the lower portions is so 
heavily compressed and so isolated from supplies of fresh air that it does not 
receive sufficient oxygen. It must be confessed, however, that the persons re¬ 
sponsible for coal storage are not willing to act upon this theory, which, if 
followed to a logical conclusion, would lead to the storage of coal in very deep 
piles on ground impermeable to air.' ’ 

A pile should be divided by alleyways into small units so that all 
parts may be easily accessible, and thus the danger of a fire spreading 
may be minimized. 

13. Ventilation of Coal Piles .—It is a generally accepted theory 
that if the air supply is entirely shut off from the coal, as with under¬ 
water storage, spontaneous combustion cannot occur. It is also 
agreed that if ample ventilation can be furnished to carry off the 
heat and keep down the temperature in a coal pile, spontaneous com¬ 
bustion will not occur. It is the intermediate condition which is dan¬ 
gerous, that is, a condition in which enough air is admitted to permit 
the coal to oxidize and heat and not enough to carry off the heat as 
rapidly as it is generated. For this reason lump coal may be safely 
stored, because there is good circulation through the pile. On the 
other hand, run of mine often cannot be safely stored, not only be¬ 
cause of the presence of an excessive amount of fine coal which ox¬ 
idizes readily, but because the openings between the lumps are filled 
to a considerable extent by the fine coal and the free circulation of 
air is prevented. Alternate stratification of coarse and fine coal, 
therefore, is undesirable, and air passages formed by the large lumps 
rolling to the bottom of a pile should be avoided. Such passages form 
a duct or flue for a sufficient amount of air to reach the fine material 
inside the pile to start oxidation. 

The practicability of properly ventilating a coal pile has been 
disputed and while the consensus of opinion in the United States is 
against ventilation by pipes, it is probable that many of the opinions 
expressed are based upon unfavorable results secured through im¬ 
properly installed and inadequate ventilation systems. Many so- 
called pipe ventilation systems have consisted merely of an occasional 
pipe into which a thermometer may be inserted for reading tempera- 


32 


ILLINOIS ENGINEERING EXPERIMENT STATION 


tures. There are of record few adequate ventilation systems being in¬ 
stalled in the United States, because such systems are expensive and 
interfere to some extent with the rapid handling of the coal; such 
systems are also considered dangerous. 

It is also stated by many that closely packed coal is so poor a 
conductor of heat that fire may start close to a ventilating pipe, and 
that it is impossible adequately to ventilate a coal pile. 

J. H. Hibben* cites an instance of apparently successful ventila- 
tionf which he describes as follows: ‘'In southern Texas several years 
ago we stored a large amount of Oklahoma mine run coal at Smith- 



Fig. 1. Method of Ventilating Coal Piles employed by the Canadian 

Pacific Railway 

ville, a coaling station near San Antonio. I experimented with one 
pile of coal by placing one six-inch glazed tile on the bottom for the 
entire length of the pile. This was the ordinary bell-shaped tile and 
it could be put together without cement, the ends butting against 
each other. In another adjoining pile an equal quantity of coal 
was stored wfithout the use of tile and the result was that in the pile 
where the tiling had been placed, there was no fire, but in the other 
pile not tiled, there was a great deal of trouble with spontaneous com¬ 
bustion. ” Hibben says further: “I am of the opinion, that pipes 
or flues do not always produce the desired results.” 

A comprehensive system of ventilation installed in Canada by 
the Canadian Pacific Railway is described by Porter J as follows: 


* Op. Cit., pp. 152-153. 

t Another instance of possible successful ventilation is referred to on page 150. 
t Op. Cit., pp. 152-153. 















THE STORAGE OF BITUMINOUS COAL 


33 


riie method in general is: first to level off a triangular piece of ground so 
that temporary tracks may be laid upon it and a steam shovel used if desired. 
A track is then laid in and hopper-bottom coal cars unload on this track, which 
is then raised on the coal and the operation repeated until an embankment of 
considerable height is made, with an inclined track from the apex of the triangle 
to the main line. When a sufiScient height is reached, the coal is side dumped or 
side shovelled and the track is gradually shifted to one side and the width of the 
pile thus increased to any desired extent. The height of the pile on the approach 
increases from nothing to about sixteen feet, and this latter height is maintained 
for the major portion of the pile. 

‘ ‘ As soon as possible after each portion of the pile reaches its f ull height it 
is ventilated by driving pointed iron rods, 1% inches or 2 inches in diameter, 
vertically down through it. After the rod reaches the bottom a bell-shaped collar 
is slipped over it and forced down about six inches into the coal, as shown in Fig. 
1. The rod is then tapped to compact the coal around it and to loosen the rod 
itself and both collar and rod are withdrawn. A rough funnel of tar paper is 
then put in the bell-shaped top of the hole to prevent pieces of coal falling in 
or being washed in by the rain. The walls of the lower part of the hole main¬ 
tain themselves without protection, and holes driven in this way ordinarily last 
for many months. The distance between the holes varies somewhat with the 
circumstances; but generally it is about sixteen inches from center to center, and 
the cost, which is almost wholly labor, amounts to approximately five cents per 
ton. 

‘ ‘ Another method, which is frequently effective, and in certain cases eco¬ 
nomically possible, is to pile the coal in layers of about two feet, allowing each 
layer to be exposed to the air for at least two days, and if possible much longer, 
before it is covered by the next layer. This method is usually effective in prevent¬ 
ing fire, if the piling is done in cool weather, but in midsummer, particularly in 
hot and sunny weather, it is of doubtful value to say the least. ’ ’ 

This description is supplemented by Dr. Porter in a private com¬ 
munication, as follows: 

‘‘I have had personal experience of the storage in Montreal of very large 
quantities of coal from Nova Scotia and elsewhere, and of one case in England 
of the Storage of Welsh coal, where it has been found possible to ventilate the 
piles cheaply and effectively by air passage ways from the surface. To my per¬ 
sonal knowledge these methods are still in successful use on a very large scale. 

‘‘In the majority of cases above referred to the ventilation was arranged 
at the time that the coal was stored, but in one or two cases under my own in¬ 
struction ventilation was successfully applied to storage piles which had begun 
to heat, and in no single case under my observation was there any difficulty in 
cooling the coal; although in one instance at least the temperature had lisen to 
133 degrees F. and was going up with a constantly increasing rapidity. 

“I am confident that the method can be successfully applied to the great 
majority of cases of storage. If the coal is known or suspected to be liable to 
heating, the ventilation holes should be driven at the time of piling and should 


34 


ILLINOIS ENGINEERING EXPERIMENT STATION 


be inspected from time to time to see that they are kept open. If the coal is of 
a less dangerous character, or if for any reason ventilation cannot be provided at 
the start, it will suffice to make frequent observations of its temperature, and 
ventilate if serious heating begins. 

‘‘I may add that the method referred to is not of my own invention or dis¬ 
covery, but that circumstances made it possible for me to examine and test it 
very thoroughly on a very large scale with the result that I am firmly convinced 
that it is a perfectly practicable and reasonably inexpensive method for com¬ 
mercial storage on a very large scale. 

‘ ‘ In spite of the numerous fires in coal piles in Canada during 1917, I am 
informed that not one single ventilated coal pile belonging to the Canadian 
Pacific Eailway has caught fire either this year or for several years. The method 
of ventilation used by the C. P. R. and copied by various other concerns is set 
forth in detail in ‘The Weathering of Coal,^ pages 152-166; the only difference 
is that their present specifications are somewhat simpler as they find that one- 
inch holes suffice driven from twenty to twenty-four inches center to center in 
parallel rows. When I described the method the company ventilated its own piles, 
but now it does the work by contract in the majority of cases at a cost of about 
five cents per ton. The Canadian Pacific Railway Company stores from a million 
and a half to two million tons of coal each year; the main part of this coal being 
piled in the summer and used during the winter and spring; and the statement 
that they have no fires where they ventilate is therefore of very great weight. 
It is interesting to note that at a few C. P. R. storage points it was not found 
practicable to ventilate the piles this year, and Mr. Britt, the Fuel Agent of the 
Company, informs me that.at these points heating has occurred and that at the 
most important of them (Fort William) they have had a very bad fire. 

“Under ordinary conditions the main part of the Montreal coal supply comes 
from Nova Scotia in ships and is quite cold when it reaches here; in fact I have 
seen ice in the coal when it was being loaded in these ships at Sydney in mid¬ 
summer. This cool coal is ordinarily handled very quickly to the storage piles, and 
the piles themselves so laid out that as little as possible sun-heated coal is buried. * ’ 

14. Testing for Fires—The, common methods of testing for the 
heating of a coal pile are: 

(1) By watching to detect evidences of steaming in the 

pile. 

(2) By noting the odor given off. The bituminous odor of 
burning coal or the odor of burning sulphur are evidences of 
heating. 

(3) By inserting an iron rod into the pile and, when drawn 
out, noting its temperature by touching with the hand. 

(4) By noting places where snow on a pile has melted. 

(5) By means of maximum temperature thermometers in¬ 
serted into pipes driven into the pile at intervals. These pipes 


THE STORAGE OF BITUMINOUS COAL 


35 


should have a conical plug in the bottom to facilitate driving 
them into the pile. After driving to the desired depth the plug 
may be withdrawn and the pipe raised a short distance from the 
bottom of the hole so that the actual temperature of the coal 
may be taken. The top of the pipe should be kept closed to re¬ 
duce the effect of outside temperatures. Instead of leaving a 
pipe in the coal pile it is sometimes necessary only to drive it 
and then withdraw it, the hole remaining open sufficiently to 
permit the insertion of the thermometer. This method obviates 
one of the greatest objections to pipes placed in the pile; i. e., 
interference with the apparatus used for removing the coal. 
Self-registering thermometers protected by a metal casing may be 
bought from any dealer in scientific instruments. They may be 
had graduated according to the Fahrenheit or the Centigrade 
scale and adjusted to various ranges of temperature, the best 
range for this work being from 0 to 220 deg. F. The cost per 
instrument is about $2.25 without armor and $4.50 with armor: 

In the experimental work carried on by Prof. J. B. Porter, of 
McGill University, a Richard thermograph was also used for record¬ 
ing temperatures.* 

15. Handling Fires .—Opinions differ widely concerning the 
critical or dangerous temperature in a coal pile. Parrf says, ‘‘Bi¬ 
tuminous coal can be stocked without appreciable loss of heat value 
provided the temperature is not allowed to rise above 180 degrees 
F.” How near to this temperature a pile should be allowed to heat 
is largely a matter of judgment. If the rate of rise in temperature 
is decreasing rapidly, it may be safe to allow the temperature to 
approach 180 degrees, but if the rise is steady and regular it is wise 
to load out the pile before this danger point is reached. The extent 
of rise allowable also depends upon the means available for loading 
out. At a plant equipped with large grab buckets or other means 
for rapidly handling the coal a higher temperature can be permitted 
than in cases in which a considerable period is necessary to load out 
the coal. A person in charge of a certain kind of coal under certain 
climatic conditions will with a little experience be able to determine 

* Porter, J. B., “Weathering of Coal,” An Investigation of the Coals of Canada, Extra 
Vol., p. 159, 1915. 

t “Effects of Storage Upon the Properties of Coal.” Univ. of Ill. Eng. Exp. Sta., Bui. 
97. pp. 7. 38, 1917. 



36 


ILLINOIS enginp:ering experiment station 


the danger point. It is impossible to set any critical temperature 
which will apply to all coals under varying storage conditions. One 
very safe rule is to he ready to remove the coal if the temperature 
reaches 150 degrees F. and to load it out if the temperature rises to 
175 degrees. 

Water has often not proved effective in putting out fires, doubt¬ 
lessly because of the fact that it was not applied in sufficient quantities 
to cool the entire mass thoroughly. An insufficient amount of water 
will aggravate rather than stop an incipient fire. One large pile in 
Chicago was soaked as completely as possible with streams from river 
fire tugs and while the fire was at the time apparently extinguished, 
it began burning again within two or three days. If the coal can be 
spread out and thoroughly saturated with water, the fire can be ex¬ 
tinguished, but often there is not sufficient ground available to permit 
proper spreading. 

In a private communication Dr. J. B. Porter says: 

“1 fully appreciate the fact that nearly everybody experienced in the stor¬ 
age of coal objects to the use of water for quenching fires in storage piles. I ex¬ 
press scepticism as to the harmfulness of water quenching. Eecent information 
strengthens this scepticism, and I have come across several cases of successful 
fire fighting by the intelligent use of water. The fuel agent of the Canadian 
Pacific Eailway states that he always recommends the use of water if the fire is 
a small one, and particularly if it is detected in an incipient stage. His practice 
is to locate the hot spot by driving test rods into the pile and then to dig a pit 
one or two feet deep right over the center of trouble; to drive and pull pointed 
rods or open pipes from it down into the heating mass and then to fill the pit 
with water, thus quenching the fire at its very center. At the same time if the 
fire is a large one he surrounds the whole heated part with a water curtain made 
by digging a ring ditch one or two feet deep and perforating its bottom with a 
row of holes as in ventilation. This ditch like the central hole is kept full of 
water from the hose, and if there is any tendency for the fire to be driven out¬ 
ward from the center, it is quenched by the water curtain. 

‘‘This method of putting out a fire is of course costly, but it is enormously 
quicker and less costly than that of digging out and results in far less loss of 
material. Personally, I am confident that it will prove successful in any ordinary 
case. ’ ’ 

Inert gases, such as carbon dioxide, have been tried as fire ex¬ 
tinguishing agents. 

16. City Ordinances Affecting Storage .—In order to determine 
if the heating of coal piles and the occasional fires resulting from 
them increase fire risks, letters were sent to the fire departments of 





THE STORAGE OF BITUMINOUS COAL 


37 


a number of cities. The following cities report that they have no 
city ordinances covering the storage of coal: Bloomington, Danville, 
Galesburg, Rockford, Decatur, Peoria, Illinois; Detroit, Michigan; 
Terre Haute, Indiana; Buffalo, New York; Superior and Milwaukee, 
Wisconsin; St. Louis, Missouri. 

The Chief of the Fire Department of Toledo, Ohio, says: “We 
have no city ordinance governing the storage of coal, but have had 
several stubborn, but no disastrous fires in large coal piles due to 
spontaneous combustion. ’ ’ 

J. C. McDonnell, Chief of the Bureau of Fire Prevention and 
Public Safety of Chicago, says: 

‘ ‘ Every fall we have fires due to spontaneous combustion of coal in piles 
but this year they started earlier than usual. Since July 1, 1917 to date (Novem¬ 
ber 14, 1917) there have been sixty-three fires in coal piles stored outside of build¬ 
ings. The quantities involved varied from 20 to 15,000 tons. In fifty cases the 
pile laid in the open and in thirteen cases only a shelter roof was provided. There 
were for the same period thirty-nine fires in coal piles inside of buildings. Thirty 
of these interior fires were in apartment buildings and the amounts involved 
varied from 5 to 1,000 tons; stored in all cases on a concrete floor. In five of 
the inside fires provision was made for ventilating the pile by means of pipes. 
Some of the outside piles have been burning for three months and are still on fire. 
One large pile at the stockyards has completely changed itself into coke. Water 
has no effect on these fires. All the coal was a poor grade of soft coal. 

The City of Chicago has the following ordinance: 

^^Coal—Storage in Buildings: Soft coal shall be stored away from the brick¬ 
work of boilers and furnaces and shall be kept only in incombustible rooms. ’ ’ 

The following regulations covering fire insurance on coal docks 
show the points to be considered in connection with the construction 
and operation of such large storage plants : 

‘ ‘ Standard Dock: Sand or earth filled, cement or concrete floor, with all iron 
or fireproof superstructure, and (or) storage sheds. 

‘^Hoisting Apparatus: To be equipped with the ‘Brown’ or similar hoist¬ 
ing apparatus with automatic shovels or buckets known as the ‘Clam’ or ‘Pick¬ 
up ’ type, for removal of coal in case of fire. 

“Boilers: To be in fireproof house. 

“Steam Pipes: To be free from wood or combustible material. 

“LubTicating Oils: Must be limited to two barrels if in house exposing 
dock, sheds, or superstructure. 

“Watchmen: To report through A. D. T. System of signal boxes to central 
station. 


38 


ILLINOIS ENGINEERING EXPERIMENT STATION 


‘ ‘ Lighting or Power: If electricity, to be in accordance with rules of 
National Board of Fire Underwriters. 

‘‘Fire Protection: To be protected by city water and city fire department 
or private .fire pump of at least five hundred gallons capacity per minute, supply¬ 
ing six-inch main extending entire length of dock, laid on ‘water’ dock so as to 
be properly drained, with suflBicient number of hydrants and amount of 2^-inch 
hose attached or on cart to cover and reach all parts of the dock, also by standard 
fire boat service. 

‘ ‘ Telegraph Fire Alarm: There shall be a telegraph fire alarm station or 
box within two hundred feet, with key at the dock. 

‘ ‘ Fire Casks and Pails or Chemical Fire Extinguishers: Should be protected 
by an adequate number of fire casks and pails or approved chemical fire extin¬ 
guishers (at least one at every Engine or Motor room on Dock or superstructure). 

“Coal: A space of at least two feet at the base shall always be maintained 
between open piles of Bituminous Slack, Bituminous Coal, and Anthracite Coal. 

‘ ‘ Anthracite coal piled or stored in frame covered or enclosed shed with 
bituminous coal shall take bituminous coal rate. 

“Anthracite coal inside non-fireproof structure must be separated from 
bituminous coal or bituminous slack outside of said structure by at least two 
feet space at base of piles, and fifty feet space from non-fireproof structure 
containing bituminous coal or bituminous slack. 

‘ ‘ Bituminous Slack Coal: Considering the disastrous experience on bit¬ 
uminous slack coal and the many fires resulting therefrom, it is not considered 
within the province of this schedule to name a rate thereon in any situation; 
and all policies covering bituminous coal should contain stipulation that the same 
is not intended to cover bituminous slack coal or screenings. 

“Bituminous Coal: If placed on, in or within two feet, if dock is filled,— 
or within ten feet if dock is not filled,—of any frame building, shed, covered or 
enclosed superstructure (excepting loading pockets or loading bins), or of any 
anthracite coal or bituminous slack, add fifty cents to the base rate. 

“Bituminous Slack: If placed on, in or within two feet, if dock is filled,— 
or within ten feet if dock is not filled,—of any frame building, shed, covered or 
enclosed superstructure (excepting loading pockets or loading bins), or any bit¬ 
uminous or anthracite coal, add one dollar to the base rate.” 


THE STORAGE OF BITUMINOUS COAL 


39 


V. Storage Systems 


17. Choice of a Storage System. —In the choice of a storage 
S3"stem the following points should be considered: 

(1) The location, size, and topography of the available 
storage ground. 

(2) The capacity of the desired installation, that is, the 
amount of coal which it is desired to load and unload in a given 
time. 

(3) The cost of the plant. 

(4) The cost of maintenance. 

(5) The cost of operation. 

(6) The amount of breakage to be permitted in handling 

the coal. 

(7) The way in which the coal is received, in open or box 
cars, or in boats. 

(8) The length of time the coal must be kept in storage. 

(9) Climate; in very cold countries under-water storage 
is impracticable for a part of the year. 

The requirements of an ideal plant are: 

(1) Adequate ground area, so that several sizes and vari¬ 
eties of coal may be stored separately. Separation into sizes has 
not been considered so important for bituminous as for anthra¬ 
cite coal, but it is becoming more important because of the in¬ 
creasing attention being given to preparation of coal for domestic 
use, and because of the fact that danger of spontaneous com¬ 
bustion is decreased by keeping different sizes separate in storage. 

(2) Adequate facilities for rapidly and economically trans¬ 
ferring coal from cars or from boats into storage. 

(3) Adequate facilities for rapidly and economically re¬ 
claiming the coal and for rapidly moving any part of the pile 
which shows evidences of taking fire. 

(4) Adequate track facilities, with gravity facilities, if 
possible, for handling cars. 

(5) Means for preventing undue breakage in handling. 

(6) Facilities for rescreening the stored coal, which, of 
course, increase the cost. 


40 ILLINOIS ENGINEERING EXPERIMENT STATION 

(7) Adequate available water supply. 

(8) Low cost of installation, maintenance, and operation 
per ton of capacity. A storage plant is in operation very ir¬ 
regularly and costs are likely to be correspondingly higher 
because of the heavy fixed charges, especially interest and de¬ 
preciation. 

Few, if any, storage plants possess or require all these ideal 
conditions. In a coke plant, for instance, breakage need not be con¬ 
sidered, except in connection with spontaneous combustion, since the 
coal is ground fine before being charged into the ovens. Storage 
facilities must of course be adapted to the various requirements and 
limitations in coal yards, power plants, railroad yards, boat docks, 
steel plants, and other establishments. 

18* Hand Operated Storage Systems .—The simplest form of 
storage consists of dumping or shoveling the coal from a car or cart 
upon a pile or into a bin or bunker, or merely of dumping it on the 
ground. From this pile it may be shoveled directly into the furnace, 
or conveyed by wheelbarrow, scraper, or bucket line to the place of 
consumption. Under this classification may be included most of the 
systems of storage used by domestic consumers, retail coal j^ards, and 
small power plants. The equipment required for such a system is 
simple, and although it is sometimes the only system applicable to a 
given situation, it is not necessarily the cheapest form of storage. 

The quantities stored in hand operated plants are relatively 
small, and the cost of storage is not usually separable from the other 
operating costs of the furnace or power plant. According to C. K. 
Baldwin,* “In transporting by wheelbarrows, gangs should be ar¬ 
ranged to give room for the wheeler to load his own barrow. Should 
two men load with the wheeler idle, add thirty-five per cent to the 
time and cost of loading; when one loads with the wheeler, add twenty- 
five per cent. In carrying loads up and down a slope, add five per 
cent for each 4 degrees of slope. Hauling by wheelbarrows is more 
economical than by carts up to a distance of about 250 feet.” 

19. Storage hy Motor Truck .—An interesting experiment is 
being carried on at the University of Illinois in the stocking of Illi¬ 
nois coal from Seam Number 6 at Georgetown under the general 


* Marks, Lionel S., “Mechanical Engineers’ Handbook,” p. 1140, 1916. 



THE STORAGE OF BITUMINOUS COAL 


41 


supervision of J. M. White, Supervising Architect, and J. A. Morrow, 
Superintendent of Buildings. The annual consumption of the Uni¬ 
versity is about 30,000 tons, the daily minimum being 50 tons and 
the maximum 150 tons. For several years it has been customary to 
stock from 4,000 to 5,000 tons on the ground in piles about twelve 
feet high. The coal is thrown by hand from railroad cars upon the 
pile, distributed by scrapers, and then hauled by wagons to the power 
house. At times fires have occurred in these piles. 

At the present time an area 114 by 196 feet is being used, and 
since this space was formerly used for tennis courts, the base is of 
firm, smooth clay. The storage space has on three sides a plank fence 
seven feet high, the posts being tied by wire rope to pegs within the 
enclosure. When the enclosure is filled to a depth of fifteen feet it 
contains about 10,000 tons. This storage plat is about one thousand 
feet from the power house where coal is received and in which is 
located the machinery for the necessary crushing and screening of the 
coal prior to storage. The coal is dumped from coal cars into a track 
hopx)er from which it is elevated. When intended for storage, the 
coal is diverted from the bunkers which feed the boilers. If the coal 
consists of screenings or the size of lump desired for storing, the 
railroad car dumps it into a pit from which it is elevated to a bin 
and then discharged into an end dumping motor truck. If lump coal 
or a size not desired for storing is received, it is crushed, if necessary, 
and screened; then by means of the storage truck which holds 3% 
tons it is taken to the storage ground. An illustration of the storage 
ground is shown as Fig. 2. 

At the storage plat a truck running on the ground first builds 
up a bed of coal from two to five feet thick from the fence toward the 
center as shown in Fig. 3. When this center becomes too small to 
provide space for handling the truck, the operation continues on 
top of the first layer already in place as shown by Fig. 4, and a second 
layer is similarly deposited, the bed thus being built layer upon 
layer. To permit the truck to work on top of the pile of coal a track 
is built of pieces of scrap plank, two by three feet, woven together 
with galvanized wire or cable, as shown in Fig. 2. The cable is more 
flexible but more costly than the wire. This track is in sections, of 
from five to eight feet, and two lines are laid on which the truck 
runs. A track of wire fencing has been tried, but it is not stiff enough 
to provide a satisfactory running base for the truck. 


42 


ILLINOIS ENGINEERING EXPERIMENT STATION 


An effort is made in storing the coal to have it thoroughly packed 
and to exclude the air as much as possible. Regular temperature 
observations are taken with an iron rod. This method differs from 
the ordinary pile storage in the tamping of the fine coal to exclude 
the air, and the experiment is being watched with a great deal of 
interest. 

A plank track for the truck is laid between the storage pile and 
the power house, and by rapid loading and fast driving a round trip 
is made in from seven to eight minutes; thus nineteen tons are stored 
per hour. Three men are used on the pile for cleaning out the truck 
and spreading the coal. The coal is separated into two parts, screen¬ 
ings being placed on one side of the storage space and lump coal on 
another, but the two piles come together. The coal is reclaimed with 
an electrically operated Jeffrey wagon and truck loader (Fig. 5). 

The expenses of handling are given in the following statement: 


Expense of Handling Coal at University op Illinois Power Plant 

Expense of labor for unloading coal per ton by hand from flat 
bottom cars at hopper with labor at 25 cents per hour. 

Lump Coal.$0.10 

Screenings.0.08 

(With Motor Truck Based on 15 Tons per hour and on Two Blocks Haul.) 

Expense of labor and teams for loading screenings by hand and hauling 
in wagons from storage pile to track hopper 300 to 500 feet away, per ton. 

Labor.$0.13 

Team.0.07 


Total ■ . . . $0.20 

Expense of labor and team for unloading screenings from bottom 
dump cars to hopper and for loading wagons from overhead bunker and 
hauling to storage pile, 300 to 500 feet away, per ton. 

Labor.$0.08 

Team.0.03 


Total . . . $0.11 

One team will haul 20 tons per hour to storage if loaded from over¬ 
head bunker and will return 7% tons per hour from storage pile to hopper 
if loaded by hand. 









Fig. 2. Coal Storage Plat and Storage Pile at the University of Illinois 



Fig. 3. Placing the First Layer of Coal on Storage Plat at the 

University op Illinois 












Fig. 4. Placing the Second Layer of Coal on Storage Pile at the 

University of Illinois 



Fig. 5. Electrically Operated Wagon and Truck Loader Used at the 

University of Illinois 








Fig. 6. Railroad Storage Pile Showing Track 



Fig. 7. Railroad Storage Pile Showing Crib for Surporting Track 


















Fig. 8. Railroad Storage Pile Showing Men at Work Raising Track 
This pile contains 25000 tons of coal 











THE STORAGE OF BITUMINOUS COAL 


47 


Expense of Storing Coal with Truck 
(Truck will handle nineteen tons per hour) 


Expense of hauling coal with truck.$0.08 

Expense of trimming pile, building roads, etc.,.0.06 

Expense of unloading lump coal by hand from flat bottom cars, 

crushing, elevating, and loading trucks.0.20 

Expense of unloading screenings by hand from flat bottom cars, 

elevating, and loading trucks.0.13 

Expense of unloading screenings from bottom dump ears, elevat¬ 
ing, and loading trucks.0.07 


Total 

Expense of Removing Coal from Storage 

1 Man running loader at 30 cents per hour 
1 Man running truck at 30 cents per hour 
1 Man leveling load at 30 cents per hour .... 

1 Man at top of pile at 30 cents per hour .... 

2 Men at plant hopper at 30 cents per hour 
2 Men at feeding loader at 30 cents per hour 

Truck operation and maintenance. 

Total expenditure per hour 
Expenditure per ton 


$0.21—0.34 


$0.30 

0.30 

0.30 

0.30 

0.60 

0.60 

0.60 


$3.00 

0.20 


20. Pile Storage from Cars without a Trestle .—A method of 
storage commonly used by railroads consists of starting a pile on the 
ground, and raising the track gradually on top of the coal pile until 
a height of from ten to twenty feet is reached, the end of the track 
being supported on a crib as shown in Figs. 6 and 7. Fig. 8 shows 
such a coal pile with men raising the track. The coal is reclaimed 
with a locomotive crane, vdth a steam shovel, or by hand shoveling 
into cars. This is a simple form of storage, but the conditions are 
favorable to spontaneous combustion, because the weight of the loco¬ 
motive and the loaded cars breaks up the coal and produces fine ma¬ 
terial in the center of the pile, while the lumps roll to the bottom 
of the outside slope and thus afford a flue through which the air may 
reach the fine material. 

Figs. 6 and 7 show the effect of dumping side dump cars which 
were evidently so loaded that the lumps were on one side and the fine 
coal on the other. The north side of the pile, Fig. 7, contained fine 
coal and the south side. Fig. 6, the lumps. This pile took fire in sev¬ 
eral places and always on the fine coal side. 













48 ILLINOIS ENGINEERING EXPERIMENT STATION 

21. Trestle Storage .—Trestle storage consists of storing coal by 
dumping it from railroad cars run upon a trestle underneath which is 
located a storage bin. This method of storage is extensively used by 
large retail dealers and by factories and power plants. The coal is re¬ 
claimed by hand, by steam shovels, by locomotive cranes, by washing 
with water into conveyors, or by other suitable mechanical means. 
Although simple in construction and low in cost of the equipment, 
trestle storage produces excessive breakage, and unless drop bottom 
cars are available the expense of unloading by hand is high. It also 
requires considerable space if coal cars are to be pushed up an incline 
by a locomotive, or if some hoisting device must be installed. 

Fig. 9 shows such a trestle arrangement in connection with a loco¬ 
motive coaling station as suggested by the International Railway Fuel 
Association. 

Fig. 10 shows two systems of trestle storage and of reclaiming 
by means of a tunnel, which may be either above or below ground, 
the coal being fed by gravity into a car or into some form of a con¬ 
veyor in the tunnel. The breakage is excessive, both in stocking and 
in removing coal. 

The introduction of a reloading tunnel decreases the cost of 
handling considerably, but with the tunnel above ground only from 
30 to 35 per cent of the coal may be reloaded by gravity. With the 
tunnel underground about 50 to 60 per cent may be thus loaded di¬ 
rectly. The cost of an underground tunnel plant is estimated as 
from 65 to 75 cents per ton storage capacity, and if the trestles are 
built of timber the expense of repairs and maintenance is considerable. 
A trestle and tunnel system using buckets for unloading and reload¬ 
ing the coal has certain advantages over the car system, but is limited 
in its capacity to from 500 to 5000 tons. 

The amount of storage space may be increased by the building 
of bulkheads along the sides of piles as shown in the upper sketch of 
Fig. 10. 

According to Norris,* 

‘‘An early type of storage-plant consists of wooden bins (Fig. 11) traversed 
by railroad tracks, from which the various sizes and types of coal are dumped, 
each in its appropriate bin. Reloading is usually accomplished by cars passing 
under the bins, either on the surface or more frequently in tunnels. 


* “The Storage of Anthracite Coal.’’ Trans., Am. Inst, of M. E., Vol. 38. p. 340 





THE STORAGE OP BITUMINOUS COAL 


49 


“To reduce the danger from fire, the movement of the reloading-cars is 
usually by gravity or by rope-haulage. The individual bins are necessarily limited 
in capacity to from 50 to 100 tons each, and an extensive plant covers a very 
large area. One such plant at the seaboard has 384 bins, reloading into cars in 
nine tunnels, and covers approximately nine acres. Such a plant costs in excess 
of three dollars per ton of capacity to erect, requires an enormous amount of 
timbei', with resulting large fire-hazard and. high maintenance-charges, and the 
operating expenses approach ten cents per ton. 

‘ ‘ A great advantage is the practicability of storing many sizes and kinds of 
coal, and keeping separate many small consignments. ’ ’ 

The following formulas and table are used by the Link-Belt 
Company for determining the horizontal pressure of a pile of bi¬ 
tuminous coal against a retaining wall. This pressure depends upon 



Fig. 9. Trestle for Coal Storage as Suggested by Fuel Station 
Committee of the International Kailway Fuel Association 


the weight of the coal per cubic foot (assumed to be fifty pounds) 
and the depth of the material at the wall, and the slope of the surface 
of the pile. 

For bituminous coal, let d represent the depth in feet. Then with 
surface of pile horizontal: 

Total pressure in pounds on wall per foot of length=6.37d^ 
Pressure on wall on lowest foot of depth=6.37 {2d —1) 

With surface of pile sloping: 

Total pressure in pounds on wall per foot of length=10d^ 
Pressure on wall on lowest foot of depth=10 {2d —1) 

Angle of repose=35 degrees. 




























50 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Table 3 gives these pressures in pounds for bituminous coal for 
every foot of depth up to 50 feet. 


Table 3 

Horizontal Pressure Exerted by Bituminous Coal Against Vertical 

Ketaining Walls per Foot of Length 


Depth 

in 

Feet 

Horizontal 

Surface 

Sloping 

Surface 

Depth 

in 

Feet 

Horizontal 

Surface 

Sloping 

Surface 

Total 

Pressure 

Pounds 

Pressure 

Pounds 

Lowest 

Foot 

Total 

Pressure 

Pounds 

Pressure 

Pounds 

Lowest 

Foot 

Total 

Pressure 

Pounds 

Pressure 

Pounds 

Lowest 

Foot 

Total 

Pressure 

Pounds 

Pressure 

Pounds 

Lowest 

Foot 

1 

6.4 

6.4 

10 

10 

26 

4,305 

325 

6,760 

510 

2 

25.0 

19.0 

40 

30 

27 

4,641 

338 

7,290 

530 

3 

57.0 

32.0 

90 

50 

28 

4,993 

350 

7,840 

550 

4 

102.0 

45.0 

160 

70 

29 

5,358 

363 

8,410 

570 

5 

159.0 

57.0 

250 

90 

30 

5,733 

376 

9,000 

590 

6 

229.0 

70.0 

360 

110 

31 

6,122 

389 

9,610 

610 

7 

312.0 

83.0 

490 

130 

32 

6,523 

401 

10,240 

630 

8 

407.0 

96.0 

640 

150 

33 

6,935 

414 

10,890 

650 

9 

516.0 

108.0 

810 

170 

34 

7,362 

427 

11,560 

670 

10 

637.0 

121.0 

1,000 

190 

35 

7,778 

440 

12,250 

690 

11 

770.0 

134.0 

1,210 

210 

36 

8,253 

452 

12,960 

710 

12 

917.0 

146.0 

1,440 

230 

37 

8,754 

465 

13,690 

730 

13 

1,076.0 

159.0 

1,690 

250 

38 

9,193 

478 

14,440 

750 

14 

1,248.0 

172.0 

1,960 

270 

39 

9,682 

490 

15,210 

770 

15 

1,433.0 

185.0 

2,250 

290 

40 

10,192 

503 

16,000 

790 

16 

1,630.0 

197.0 

2,560 

310 

41 

10,669 

516 

16,810 

810 

17 

1,840.0 

210.0 

2,890 

330 

42 

11,236 

529 

17,640 

830 

18 

2,063.0 

223.0 

3,240 

350 

43 

11,797 

541 

18,490 

850 

19 

2,298.0 

236.0 

3,610 

370 

44 

12,331 

554 

19,360 

870 

20 

2,.548.0 

248.0 

4,000 

390 

45 

12,968 

567 

20,250 

890 

21 

2,809.0 

261.0 

4,410 

410 

46 

13,478 

580 

21,160 

910 

22 

3,083.0 

274.0 

4,840 

430 

47 

14,100 

592 

22,090 

930 

23 

3,369.0 

287.0 

5,290 

450 

48 

14,679 

605 

23,040 

950 

24 

3,669.0 

299.0 

5,760 

470 

49 

15,275 

618 

24,010 

970 

25 

3,981.0 

312.0 

6,250 

490 

50 

15,925 

631 

25,000 

990 


Note. —Weight of coal is taken as 50 pounds per cubic foot in calculating this table. 


In the parallel trestle system (Fig. 12) two parallel trestles from 
ten to fifteen feet high are located about thirty feet apart. A loco¬ 
motive crane runs on one of these trestles, unloads coal from railroad 
cars on the other trestle, and deposits it for storage in a pile the 
length of which is limited only by the length of the trestle. The 
crane and the cars are used interchangeably on the trestles so that 
the storage system consists of parallel piles. A pile of anthracite 
twenty-five feet high, whose angle of repose is 27 degrees, contains 
sixty-seven tons per running foot. For bituminous coal a pile of the 
same height, with an angle of repose of 40 degrees, contains 63 tons 
per running foot. 





























THE STORAGE OF BITUMINOUS COAL 


51 


22. Storage with Side Dump Cars .—The Chicago, Wilmington 
and Franklin Coal Company at the Orient Mine, Franklin County, 
Illinois, has installed a very simple but effective storage system de¬ 
signed by G. B. Harrington, President of the Company, in which side 
air dump contractors’ cars are used. These cars hold twelve cubic 
yards, but with sides built twice the usual height they have a capac¬ 
ity of about twenty-five tons of coal. In a level field located a short 
distance from the tipple, an elevated track was built, as shown in 
Fig. 13, from which the side dump-cars empty the coal alongside the 



Fig. 10. Trestle and Tunnel Systems, Showing an Above-ground and a 

Below-ground Tunnel 

track. Two locomotive cranes with two-yard clam-shell buckets, one 
on each side of the trestle, move the coal into storage piles parallel 
with this main elevated track. The dump cars are loaded at the tip¬ 
ple, as shown in Fig. 14. 

The purpose of this plant is to permit continuous operation of the 
mine on days or parts of days when there is a failure in the railroad 
car supply and the mine would otherwise have to shut down. When 
railroad cars are scarce, the air dump cars take the output to the 
storage trestle. The cranes move the coal back into the storage piles 












52 


ILLINOIS ENGINEERING EXPERIMENT STATION 


and keep the dumping points clear. On da^'S when cars are plentiful, 
the process is reversed and coal is loaded by the cranes from the 
storage pile into the air dump cars which return it to the head of the 



Fig. 11. Bin and Tunnel Type of Storage System with Bulkheads 

(Reproduced from “The Storage of Anthracite Coal” by R. V. Norris. 
Trans. Am. Inst, of M. E., Vol. 38, p. 314.) 


screening plant through the medium of a track hopper and elevator. 
In case it is desired to ship mine run coal, railroad cars may be loaded 
directly by the cranes from the storage pile. 



ZOrr. 


ZIQ4 


BITUMINOUS 

. 25FT. 


BITUMINOUS 
- - 


ANTHRACITE 


TOTAL CAPACITY OP PILE, WITH SUPfACC TffACK OPCN. 40 TONS AEH AUNNING FT. 
** *» »* »* ** CLOSCD. SS »• »» 


46' 

ANTHRACITE 


TRCSTLi 


SuRRACe TRACK 


Fig. 12. Parallel Trestle System of Storing Coal 


The storage plant could not be located close to the tipple, because 
no level or suitable ground was available, the mine being situated on 
a hill side. 





















































































Fig. 13. Storage Track and Side Dump Cars at the Orient Mine of the 
Chicago, Wilmington and Franklin Coal Company 



Fig. 14 


Loading Dump Cars at the Tipple, Orient Mine of the Chicago, 
Wilmington and Franklin Coal Company 



















Fig. 15 


Side Hill System of Storage 




THE STORAGE OF BITUMINOUS COAL 


55 


When not in use for storage the dump cars and cranes are useful 
in handling refuse, ashes, machinery and equipment, and for grading 
and other work at the mine. 

The capacity of the Orient No. 1 Mine is from 4,500 to 5,000 tons 
a day, and the storage equipment described has proved effective in 



Fig. 16. Clam-Shell Bucket (top) and Orange-Peel Bucket 

helping to maintain a fairly uniform output with an inadequate and 
irregular car supply. It takes about thirty minutes to load a string 
of fifteen dump cars at the tipple, to run them down to the storage 
trestle about a mile away, to dump them, and to return the empty 
cars to the tipple. The trestle and track hopper are designed to 











































56 


ILLINOIS ENGINEERING EXPERIMENT STATION 


save unnecessary breakage and the coal shows practically no degrada¬ 
tion in the few days during which it is held in storage. 

In normal times these dump cars cost about $1,350.00 each and 
the cranes about $5,800.00 each. The trestle used is about nine feet 
high and costs about nine dollars per running foot. 

A number of other varieties of dump cars has recently been 
used for similar storage purposes at other plants. In one instance 
all steel cars of thirty cubic yards capacity have been substituted for 
the smaller cars. 

23. Side Hill Storage. —In the side hill system of storage (Fig. 
15) a steep hill side is utilized, and coal is unloaded by gravity from 
cars on a track or trestle at the upper side of the storage yard. At 
the bottom of the pile a retaining wall holds back the coal, and be¬ 
low this cars are loaded by chutes running into the pile. In order to 
increase the capacity of such a plant a level space is usually provided 
back of the retaining wall, but this produces a dead space from which 
the coal must be shoveled and in which when using the chutes a large 
amount of coal is left as dead stock. While side hill storage appears 
to be ideal in its arrangement and possibilities, there are compara¬ 
tively few situations in which it can be applied conveniently and 
profitably. 

24. Self-filling Buckets. —The type of bucket used for hand¬ 
ling coal in connection with locomotive cranes, traveling bridges, and 
other mechanical storage devices is a matter of some importance. 
Coal must be handled quickly and in such manner as to prevent ex¬ 
cessive breakage. 

The two types of self-filling buckets most generally used in the 
handling of coal are the so-called clam-shell and orange-peel types 
(see Fig. 16). Both types are reported to be satisfactory. 

25. Use of Mast and Gaff Arrangement in Storage. —In the 
simpler forms of coal handling machinery the ordinary mast and gaff 
arrangement (Fig. 17) is cheap and efficient when rapidity of hand¬ 
ling and maximum storage are unnecessary. 

The traveling cableway (Fig. 18) is more efficient so far as 
utilization of ground area is concerned but is slow in stocking and 
reclaiming where long lengths of travel are necessary. 




Fig. 17. Automatic Grab on Mast and Gaff with Shuttle Cable Eailway 



Fig. 19. Locomotive Crane with Clam-shell Bucket Unloading Coal 





































THE STORAGE OF BITUMINOUS COAL 


59 


26. Locomotive Crane Storage .—The device most generally used 
for storage except when very large special equipment is necessary, 
is the revolving locomotive crane equipped with a clam-shell or or¬ 
ange-peel bucket. Locomotive cranes are used particularly in large 
industrial plants. 

Fig. 19 shows a locomotive crane operating from a low trestle 
and placing coal either into the bunker or on stock pile. 




Fig. 18. Traveling Cableway 


These cranes are self-propelled at the rate of from four to eight 
miles per hour, and may also be used for shifting cars over small 
distances, thus eliminating the necessity of a locomotive. They are 
generally operated by steam, although sometimes electric power is 
employed. The revolving superstructure is supported on a base which 
rests on four to eight wheels, the eight wheeled car body being prefer¬ 
able for switching and for general work. The gage of the track on 
which these cranes run may have to suit existing conditions at any 
one plant, but when choice is possible the gage should be approxi¬ 
mately as follows: 

4 feet, 8% inches for a maximum radius of swing of 30 feet. 

14 feet, 6 inches for a maximum radius of swing of 45 feet. 

16 feet for a maximum radius of swing of 60 feet. 

20 feet for a maximum radius of swing of 100 feet. 






















60 


ILLINOIS ENGINEERING EXPERIMENT STATION 


The operator, who is on the covered platform, fills the bucket, and 
as he raises it the crane revolves to the unloading point. The speed 
of operation varies greatly with the operating conditions, but the speed 
generally averages about one bucket per minute. 

Prices of machinery quoted during war times may be misleading, 
since they are generally higher than in normal times and they vary so 
rapidly that any quotation given by a manufacturer holds for only a 
short time. On account, however, of the extensive use of the locomo¬ 
tive crane for storing coal the following prices quoted by several firms 
in April, 1917 are presented: 

(1) Standard 14-ton, 4-wheel steam locomotive crane with 
boom 35 feet, 4 inches long and double drums for operating ■ 
a 54-cubic-foot grab bucket, f. o. b. Champaign, $11,475. This 
crane will handle from 1% to 1^ tons per minute, and under 
average operating conditions should easily make from sixty 
to ninety bucket trips per hour. 

(2) Fourteen-ton, 4-wheel steam locomotive crane with 
boom 40 feet, 91/2 inches long, and double drums, for handl¬ 
ing a 40-foot grab bucket, f. o. b. to Champaign, $11,515. This 
crane will handle from 1800 to 2000 pounds per minute at 
about the same rate as crane (1). 

(3) Standard 8-wheel crane with boom 40 feet, 9^2 
inches, and double drums for handling a 54-cubic-foot grab 
bucket, $14,600. 

For a small amount of travel the 4-wheel crane will 
handle as much coal per day as the 8, but on account of its 
rigid base it is not as suitable for moving cars on curves or 
over general yard tracks. 

(4) Fifteen-ton, 8-wheel crane with boom 40 feet, 9^ 
inches to handle a 50-cubic-foot bucket at 40-foot radius, net 
shipping weight 100,000 pounds, $14,600. 

(5) Similar but heavier crane to handle 40 cubic feet at 
50-foot radius, $14,960. 

(6) Standard gage steam operated revolving locomotive, 
8-wheel double track crane with 50-foot boom, and two-cubic- 
yard clam-shell bucket, $14,300. 

(7) Standard gage steam operated revolving locomotive 
crane, 4-wheel 42-foot boom 2-cubic-yard clam-shell bucket, 
$11,893. 


THE STORAGE OF BITUMINOUS COAL 


61 


J. S. Shearer, of the Industrial Works, Bay City, Michigan, says: 

some cases a crane with a 45-foot boom is able to unload the far end 
of the car standing on the same track as the crane. At the present time, however, 
when cars are being made longer than before, we find it to be almost always the 
case that a boom giving a radius of fifty feet is necessary. If a crane is to work 
on a track parallel with one from which the coal is to be taken a shorter boom is, 
of course, possible. 

“We formerly figured on the daily operating cost as approximately one 
dollar an hour. This contemplates using the crane ten hours a day and in the 
cost are included the services of an engineer, a helper on the ground, interest, de¬ 
preciation, fuel, supplies, and repairs. At the present time when the first cost of 
equipment is higher and the cost of all supplies higher, we think you would have 
to take $1.50 to $2.00 an hour as the approximate charge. Under average operat¬ 
ing conditions the crane would have no difficulty in handling from forty to seventy- 
five tons per hour. This would make the cost per ton somewhere around three 
cents. We formerly found that the cost averaged about two cents, sometimes 
being less and sometimes more.’’ 

The Storage of Coal Committee of the International Kailway Fuel 
Association* says with regard to storing with a locomotive crane: 

‘‘We would suggest the employment of a locomotive crane with clam-shell or 
similar device for unloading and reloading storage coal, where the amount to be 
stored is less than five thousand tons and where the daily issues are small enough 
to permit of its use. This arrangement requires no preliminary preparation and 
little or no additional expense. The cost of unloading from the road cars may 
be cheapened when dump bottom cars are available, by unloading them on tracks 
that have been blocked upon old car and bridge timbers, so placed and arranged 
that the structure can be raised bodily from time to time, by the use of a locomo¬ 
tive crane, working on an adjacent and parallel track.” 

The ways in which a locomotive crane may be used in connection 
with storage of coal are numerous, and onlj^ some of the typical ones 
will be given. Catalogs of the manufacturers of these cranes are the 
best source of information regarding their uses. 

At the coal yards of the Commonwealth Edison Company a loco¬ 
motive crane with a two-yard clam-shell bucket will ordinarily un¬ 
load from ten to fifteen cars per day of eight hours. One operator 
has loaded as many as twenty-five cars in ten hours. The amount is 
less in cold weather and in handling large coal. Two men are em¬ 
ployed on the crane, and two shovel out the cars and clean the track. 
The crane can load faster than it can unload the cars. 

According to W. L. Abbott, Chief Engineer of the Commonwealth 
Edison Company of Chicago, that company aims to keep in storage 


* “Storage of Coal.” Proceedings, Vol. VII, p. 152, 1915. 



62 


ILLINOIS ENGINEERING EXPERIMENT STATION 


at its various city stations from 100,000 to 150,000 tons of coal and at 
the Glenn storage yards, outside the city limits, about 260,000 tons. 
All varieties of Illinois coal are stored, but those of southern Illinois 
are preferred. Coal is placed in storage and reclaimed by locomotive 
crane at an estimated expense of five cents per ton for unloading and 
five cents for reclaiming. This covers labor and materials only. 

According to the storage scheme devised by Mr. Abbott, coal is 
stored on the ground in continuous pyramidal piles twenty-five feet 
high, each pile being between and parallel with two pairs of railroad 
tracks, as shown in the upper sketch, Fig. 20. The tracks bounding 





Fig. 20. Arrangement of Tracks and Storage Piles Employed by the 
Commonwealth Edison Company in Open Storage 

the piles are eighty feet, center to center, and the tracks between the 
piles twenty feet, center to center. The crane can operate from either 
track while loading or unloading cars on the parallel track. These 
piles contain about thirty tons per foot of length. 

This company is now preparing a new storage yard for the ac¬ 
commodation of 120,000 tons of coal in which the general arrangement 
will be similar to that shown in the upper view. Fig. 20, with the dif¬ 
ference that the ground under the coal space will be excavated to a 
depth of five feet below the surface, and the spoil will be used to raise 
the grade of the tracks five feet above the ground level, thus render- 












































THE STORAGE OF BITUMINOUS COAL 


63 


ing possible a coal pile of a total depth of thirty-five feet and contain¬ 
ing forty-five tons per foot of length, as shown in the lower sketch, 
Fig. 20. 

27. Parallel Track Storage. —Fig. 21 shows a double track stor¬ 
age arrangement for a locomotive coaling station, the coal being piled 
between the parallel tracks, and loaded and unloaded with a locomotive 
crane. 



Fig. 21. Parallel Track Storage System 

(Reprinted from the Proceedings of the International Railway Fuel Association) 



Fig. 22. Eailway Trestle and Crane System of Storage 

(Reprinted from the Proceedings of the International Railway Fuel Association) 


28. The Trestle and Crane Systeyn. —Fig. 22 shows a combined 
trestle and locomotive crane system suggested by the Fuel Station 
Committee of the International Railway Fuel Association. A timber 
trestle erected adjacent to the track on which locomotives are coaled 
and fireboxes cleaned provides a runway for a locomotive crane 
equipped with a clam-shell or grab bucket. 
































































































64 


ILLINOIS ENGINEERING EXPERIMENT STATION 


The Committee* states: 

“It is advisable to place a plank wall or barrier along the side of the trestle 
contiguous to the storage pile, to prevent coal from accumulating under the 
trestle, thus obviating the necessity of reclaiming such accummulation by the 
employment of laborers. 

“Adjoining the trestle, sufficient ground is reserved for the storage pile, 

which will require a strip of land about sixty feet wide, and varying in length 
in proportion to the capacity of the pile. 

“The plan provides for a storage capacity of twenty-eight tons per lineal 
foot of coal pile. 

‘ ‘ The operation of this plan is as follows: 

“Coal will be delivered to the coal-receiving track in gondola cars of practi¬ 
cally any type, from which it will be removed and transferred to the storage pile 
by the locomotive crane. 

“When it is desired to reclaim the storage coal, the foregoing operation is 
reversed, the crane picking up the coal from the pile and reloading it in cars, which 
are than hauled away to be discharged at any of the coaling stations served by 
the storage plant. Or, if desired, this plant may be used for coaling engines either 
from cars on the receiving track or from the storage pile. It is not considered 
advisable to use this plant as a locomotive coaling station at terminals where a 
large number of engines are coaled, as delay might be caused in the rapid move¬ 
ment of engines, due to the comparative slowness of the crane as a coaling device. 
In the event of a serious breakdown in the coaling station, the crane would afford 
a very good emergency device for coaling engines while repairs were being made 
to the coaling station. 

‘' From somewhat meager figures available it is estimated that coal can be 
stored from cars, or reloaded from storage at about two and one-half cents per ton. ’ ’ 

Fig. 23 shows a McMyler locomotive crane placed on an elevated 
traveling platform. 

The Clinchfield Fuel Company with mines at Dante, Va., has a 
storage plant at Spartanburg, S. C., which has a capacity of 150,000 
tons and in which from 10,000 to 130,000 tons are kept in storage for 
periods of from six months to two years. The storage plant is 994 
feet by 240 feet with a railway running through the center of the 
storage space. On each side of this trestle are tracks for a traveling 
crane. The trestle is approximately twenty feet high and incoming 
coal is dropped through this trestle from hopper bottom cars. A 
McMyler traveling crane with a 75-foot boom and a 2.5-ton grab 
bucket picks up the coal from the foot of the trestle and piles. The 
crane has a capacity of two hundred tons per hour. 

The storage space is floored with two-inch planks nailed securely 
to timbers. The tops of these timbers are set flush with the ground level. 

* “Storage of Coal.” Proceedings, International Railway Fuel Association,” Vol. VII 
p. 156, 1915. 




Fig. 23. Locomotive Crane Placed 
Elevated Traveling Platform 


ON AN 









THE STORAGE OF BITUMINOUS COAL 


67 


The pile is continuous, and from thirty to forty feet high. The 
expense of storing is as follows: 

Unloading or Storing Expense, June 24-October 4, 1912, including 
pay roll, repairs, supplies, power, depreciation at 10 per cent per 
annum and interest at 5 per cent. .$8441. 

Tons handled 125,696; expenditure per ton.$0.0671 

Reloading expense, October 8,1912-January 31,1913 . . $8496. 

Tons handled 129,778; expenditure per ton. 0.0655 

Total average expense of storing and reclaiming at 13.26 cents per 
ton. Unloading expenses May 1—August 1, 1914, tons handled 
131,949; expenditure per ton.0.0618 

The coal is from Russell County, Va., and is run of mine with 
about sixty per cent lump over a two-inch screen. No attempt is made 
to remove slack. It has the following composition: 


Per cent 


Moisture.2.8 

Volatile Matter.34.9 

Fixed Carbon.56.6 

Ash.5.8 

Sulphur ..6 

B. t. u.14150 


It is placed in storage about six to ten days after being mined and 
during the summer time; thus the surplus from the mine is stored 
when the demand is below the output of the mine, provides for extra 
demand in winter, and insures customers against strikes and other 
contingencies. 

There is no difference in the price of stored and fresh coal. In 
fact storage coal is sometimes higher because of ‘‘spot” demand. No 
material decrease in heating value is noted, but there is a decrease 
of ten per cent in lumps. Slight heating occurs after three or four 
months, and in some cases reaches 170 degrees F. The temperature 
is tested by tubes placed in each pile. No means, however, are taken 
to prevent heating, but if it occurs the coal is loaded out at once and 
shipped. 

29. Circular Storage .—The peculiar adaptability of the locomo¬ 
tive crane to operation in a circle and its easy portability have led to 
a number of so-called circular storage systems. Some of these have 
been patented by the J. M. Dodge Company. Fig 24 illustrates a 









68 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Dodge type of circular system with a capacity of from 6,000 to 40,000 
tons. The coal is dumped from a railroad car into a track hopper 
from which it is taken by a long radius locomotive crane and self¬ 
filling bucket and dumped upon piles, the circular crane track being 
finally completely covered. A number of piles may be joined, as 
shown. In reloading, the crane takes the coal from the pile and loads 
it directly into the car. The rate of handling in such a storage system 


Stocking Keclaiming 

Labor and supplies per ton.$0,025 $0,014 

Power and superintendence.0.016 0.014 


$0,041 $0,028 



Fig. 24. Dodge Type of Circular Storage System 


varies from 40 to 200 tons per hour, according to the size of the bucket 
and crane used. The length of the boom depends upon the storage 
capacity required. The estimated expense of operation is as follows: 

An elaboration of this system by which concentric storage piles 
may be built up is shown by Fig. 25. By rehandling the coal in such 
a system from one pile to another an almost unlimited capacity may 
be secured. 































THE STORAGE OF BITUMINOUS COAL 


69 


Table 4 gives the storage capacity with this system for cranes of 
different radii and for the two conditions, first where the crane tracks 
are covered, and secondly, where the crane trucks are left uncovered. 
The railroad tracks are assumed to be twenty-seven feet center to 
center and the coal to weigh fifty pounds per cubic foot. 



Fig. 25. Twenty-five-Thousand-Ton Storage Plant 


The storage plant of the Old Ben Coal Corporation at its No. 9 
Mine at West Frankfort, Franklin County, Illinois, (Fig. 26) is a 
modified circular storage. At this mine five sizes of coal are prepared 
for the market by means of spiralizers and seven sizes are shipped. 

When there are no cars for direct shipment, the coal instead of 
being deposited in the shipping bins, aa, is carried by the apron con¬ 
veyors, Ijl), delivered to a cross conveyor, c, and then deposited by the 
chute, d, upon the pile, e. It is then taken by a locomotive crane, /, 
which has a boom 110 feet long operating over a 100-foot radius. The 
capacity of the plant is about 300,000 tons. By means of an addi¬ 
tional track outside the storage pile, the capacity could be greatly in¬ 
creased. 




























70 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Table 4 

Capacity op Circular Crane Storage 
(Link-Belt Company) 


Radius 

of 

Crane 

(Feet) 

Crane Tracks Covered (Feet) 

10 

15 

20 

25 

30 

35 

40 

35 

40 

45 

50 

55 

60 

65 

70 

75 

80 

85 

90 

95 

100 

110 



7,000 

9,600 

11.500 
15,000 

17.600 

22.700 

25.600 

30.500 

32.600 
39,440 

43.600 

46.300 
53,220 

57.700 

71.300 







12,400 

16,000 

19.500 
24,000 

28.500 
32,800 

39.100 
44,300 
49,700 

56.100 

58.100 
66,540 
74,000 
89,000 











25.300 
29,200 
35,400 

39.100 

46.300 
55,600 
60,800 

68.300 

70.100 
78,800 

89.300 
107,700 









42,100 

46,900 

54.300 
63,800 
69,600 

82.300 
84,250 

92.300 
103,900 
123,800 













83.200 
94,400 

96.200 
106,200 
123,000 
142,300 




34.500 
39,130 

43.500 

53.500 





Radius 

of 

Crane 

(Feet) 

Crane Tracks Uncovered (Feet) 

10 

15 

20 

25 

30 

35 

40 

35 

40 

45 

50 

55 

60 

65 

70 

75 

80 

85 

90 

95 

100 

no 



6,050 

6,850 

9,280 

11,200 

13.500 
15,900 

19.400 

22.300 

25.300 

30.100 

34.400 

41.500 
43,860 
47,000 

60.100 







8,875 

11,720 

14,000 

17.100 
20,400 
23,700 

29.600 
30,800 

37.600 
41,900 

52.100 
54,500 
60,000 
74,000 











17,600 

21,000 

25.100 

29.100 

34.200 
39,500 

45.200 
50,700 
60,800 
63,000 
69,000 
85,000 









29.600 

34.500 
39,300 

45.800 

53.600 

60.500 

70.800 

72.100 

79.100 

94.800 













61.500 
71,100 
80,600 

82.500 
90,600 

106,500 




31.200 
32,900 

36.200 
45,500 






In reclaiming, the crane delivers the coal upon the pile, e, which 
feeds into the boot, g. Thence by means of a gate and feeder the coal 
is delivered to the elevator, li, which in turn delivers it to the apron 
conveyor, i, which returns it to the screens and the spiralizers. If 
possible, coal of dilferent sizes in storage is kept in separate piles, 
but if the plant is crowded all sizes are stocked together. 

According to D. W. Buchanan, President of the Company, the 
cost of such a plant erected under war conditions would be approxi¬ 
mately $100,000. The expense of operation covering labor and sup¬ 
plies for stocking and reclaiming is about five cents per ton. 















































































THE STORAGE OF BITUMINOUS COAL 


71 


At the No. 8 mine of the same company, coal is stored by un¬ 
loading cars Muth locomotive cranes upon piles parallel with the track 
and reclaiming it by means of the cranes. 

At the mines of the Old Ben Corporation located in and near 
Christopher, a method of storage similar to that described as being 
in use at the Orient Mine of the Chicago, Wilmington and Franklin 
Coal Company (p. 51) has been established. This company has two 
mines at Christopher and two at Buckner. One mine of each pair has 



z/T/f Tracks 


Fig. 26. Arrangement of the Storage Plant of the Old Ben Coal 
Corporation at West Frankfort, Illinois 


been chosen as a storage point and the system of storage employing 
side dump cars and a locomotive crane has been established. 

Many other adaptations of the semicircular or circular pile may 
be made, as, for instance, by placing the pile near a power house or a 
coaling station so that the crane in reclaiming can deposit the coal in 
a depressed hopper from which it is elevated into the power house, or 
coaling station (Fig. 27). For locomotive coaling the crane may de¬ 
posit the coal into an overhead bin spanning the track as shown in 
Fig. 28. 

According to the Storage of Coal Committee,* 


* Proceedings, International Railway Fuel Association, Vol. VII, p. 159, 1915. 













































72 


ILLINOIS ENGINEERING EXPERIMENT STATION 



‘ ‘ The locomotive crane has been adopted by the Louisville & Nashville R. R., 
at three locations, where large mechanical coaling stations of reinforced concrete 
and steel construction have been erected (Fig. 29). 

‘ ‘ The receiving hopper is enlarged at the back to form a pit of sufficient size 
to accommodate the grab bucket of the crane. The crane is located on a circular 
track back of this hopper, this track centering on the hopper. Coal is dumped 
into the hopper from the receiving track, and handled to storage by the crane. 
In reclaiming from the storage pile, coal is picked up by the crane and discharged 
into the hopper, from which it is handled to the overhead coal pocket in the usual 
manner. 


10.000 TON 


TRAVELLING 

WEIGHING 

HOPPER 


“A special crane of 110 feet radius is used by the Louisville & Nashville R. 
R., the crane track gage being 20 feet. In this way they secure a 22,000 ton stor¬ 
age with a 12-foot depth of pile. The crane uses a 3%-ton bucket, and has a 
working capacity of 150 tons per hour. 

‘^An ordinary crane with a 40 or 60-foot boom could be used as well, but of 
course the size of storage pile would be reduced accordingly. The smaller crane 
would have some advantage in that it might be used for other purposes when 
not required to handle storage coal. 

“For the most economical operation, such a crane should be electrically 
operated. Such a plant is estimated to cost $23,000.00. ’ ’ 


Fig. 27. Semicircular Storage Adapted to Locations near Power House or 

Coaling Stations 


7136 



























Fig. 28. Locomotive Crane Eeclaiming Coal and Dumping into Bins 


ABOVE KaILROAD TrACKS 










THE STORAGE OF BITUMINOUS COAI. 


75 


30. Steeple Toivers .—Instead of a locomotive crane a steeple 
tower of steel or wood (Fig. 30) may be used. From such a tower a 
boom projects over the vessel or car into which the bucket is lowered. 
Upon being hoisted it is drawn back and dumped into a pocket from 
which the coal passes into a car, or is transferred by some other 
method to the point at which it is to be stored or used. These towers 
may be either fixed or movable. They usually run on tracks parallel 
with the water front. The booms are generally made so that they may 
be drawn back when not in use. With a 1%-ton bucket such a tower 
will unload and deliver to conveyors about 150 tons per hour. 



20 rT. CAUGC CrUNC TRACK 

SPECIAL LOCOMOTIVE CRANE 
WITH HO PT. RADIUS 
CLECTRiCALLV OPERATED 


22000 TONS 
CROUNO STORAGE 
12 fT. DEEP 


RECEIVING HOPPER 


eUCKCT PIT 


PLAN or 22000 TONS STORAGE 
OEVELOPtO BY HO FT. LOC. CRANE 


Fig. 29. L. & N. R. R. Type of Mechanical Coaling Station 

(Reprinted from Proceedings of the International Railway Fuel Association) 


The storage yard of the Western Coal and Dock Company, Wau¬ 
kegan, Illinois, (Fig. 30) has three towers which deliver coal into cars 
running on a trestle about the storage yard. 

By extending the boom backward through the tower, (Fig. 31) 
the buckets may be discharged into cars or upon a small stock pile. 
The tower may carry a self-contained hoisting unit or man trolley 
which moves along the boom and contains the drums and motors re¬ 
quired to operate the bucket. 


31. The Hunt System .—A common method of transferring coal 
to a pile is to dump it from a bucket into a bin from which it is dis¬ 
charged into a car which runs by gravity upon a trestle and as it 





























































76 


ILIJNOIS ENGINEERING EXPERIMENT STATION 


advances raises a counterwieiglit. Such a system is illustrated by 
Fig. 32. The car is dumped automatically by a catch which may be 
set at any point along the trestle. As soon as the car is empty it is 
drawn back by the counterweight to its starting point and is then 
ready for another load. By means of a series of radiating trestles a 
large storage area may be reached by this system. 

32. Bridge Storage .—A common form of transfer and storage 
is by means of a steel bridge which is usually movable about the stor¬ 
age yard and which serves as a support for a grab bucket, a belt, or 
other conveying devices. When both ends of the bridge are movable 
in a straight line, it becomes a gantry crane and may be made to cover 
any desired length of dock or storage yard, although because of the 
necessity for loading or unloading a cargo quickly these bridges do 
not generally travel over great distances. Fig. 33 shows a simple 
form of McMyler bridge gantry crane fitted with an electrically oper¬ 
ated man trolley which serves a storage plant of about 50,000 tons. 

A combination of unloading tower and traveling bridge utilizes 
to the fullest extent the ground area available, gives maximum stor¬ 
age, and usually provides maximum speed with minimum labor for 
both stocking and reclaiming. Steam or electricity is used for motive 
power, the choice being governed by the expense of operation. 

Bridges may be divided into four classes according to the method 
of handling the coal on the bridge, as follows:— 

(1) Rope trolley in which the bucket is operated from a 
stationary house on the bridge. Fig. 34 shows a bridge of this type 
built by Heyl and Patterson for the Reiss Coal Company at Supe¬ 
rior, Wisconsin. The span of the bridge is 380 feet, the length of 
travel at present 1650 feet, and the storage capacity of the plant 
450,000 to 600,000 tons. 

(2) Man trolley in which the bucket is operated directly 
from a moving cab. Buckets holding from ten to twelve tons are 
used on this type of bridge. Fig. 35 shows two man trolley coal 
storage bridges built by the Wellman-Seaver-Morgan Company 
for the Indiana Steel Company, and equipped with 7^-ton 
buckets. 

(3) Belt conveyor type in which the bridge serves as a sup¬ 
port for a belt conveyor which, by means of an automatic trip, 
dumps the coal at any desired point. 



Fig. 30. Towers Employed in Handling Coal, Western Coal and Dock 

Company, Waukegan, Illinois 



Fig. 31 


Traveling Tower or Direct Unloader 

















Fig. 32. Hunt System of Handling Coal 



Fig. 33. Bridge Gantry Crane with Electrically Operated Man Trolley 















Fig. 34. Coal Handling Plant of tfie Eeiss Coal Compana" at 

Superior, Wisconsin 



Fig. 35. Man Trolley Coal Storage Bridges of the Indiana Steel Compana^ 











































































Fig. 36. Belt Conveyor Type of Bridge op the Inland Steel Company 



Fig. 37. Movable Bridge with Side Dump Cars 


































THE STORAGE OF BITUMINOUS COAL 


81 


The belt conveyor type of bridge is illustrated by Fig. 36 
which shows a large coal handling plant at the works of the Inland 
Steel Company at Indiana Harbor, Indiana, built by the Robins 
Conveying Belt Company. 

(4) Cable road bridge on which a car runs. Fig. 37 shows a 
system in which the bridge moves over the length of the storage 
yard. Small side dump cars pass from a track running length¬ 
wise of the storage yard upon the bridge from which they are 
dumped. The coal is reclaimed by a clam-shell bucket operated 
from the same bridge. 

According to C. K. Baldwin* the capacity of storage bridges 
varies from 100 to 500 tons per hour, according to the size and speed 
of operation of the grab buckets or other carrying devices employed. 
The capacity of buckets varies from two to ten tons, the smaller sizes 
of from two to five tons being the more common. The span of the 
bridge usually depends upon the available storage space and may be 
as much as five hundred feet. The speed of the bridge varies from 
50 to 200 feet per minute and that of the man trolley from 500 to 1500 
feet per minute. 

Fig. 38 shows a system of traveling bridges designed by Roberts 
and Schaefer Company, of Chicago, for the Clarkson Coal and Dock 
Company at Duluth, Minnesota. These bridges have a capacity of 
three hundred tons per hour from the vessel to the dock six hundred 
feet distant. 

Fig. 39 show^s a parallel track storage yard for a locomotive coal¬ 
ing station as suggested by the International Railway Fuel Associa¬ 
tion Committeef. The coal is unloaded and also reclaimed by means 
of a clam-shell bucket operated from a traveling bridge. The reloaded 
coal is delivered into a hopper at a stationary screening plant and 
elevated to the screens for preparation. 

Fig. 40 shows the ground plan of a storage yard which is designed 
to handle as much as 20,000 tons of storage coal at a very low cost, by 
the use of a bridge and a traveling bucket. The coal is taken out of 
cars and placed in storage by means of the bucket, the labor being 
performed by the regular coal chute force during the dull seasons of 
the year, thus reducing greatly the expense of labor. The coal is re¬ 
covered by picking it up with the bucket and delivering it to the con- 


* Marks, L. S., “Mechanical Engineers’ Handbook,’’ p. 1131, 1916. 
t Proceedings, Vol. VI, p. 115, 1914. 



82 


ILLINOIS ENGINEERING EXPERIMENT STATION 


veyor chain which discharges it directly into the receiving hopper of 
the chute. 

The following estimate for the expense of stocking with a bridge 
tramway is given by the Link-Belt Company (cost, interest, and de¬ 
preciation not included) : 

Labor and Supplies for stocking per ton.$.041 

Power and Superintendent’s expenses.014 

Total.$.055 

Labor and Supplies for reclaiming per ton.0385 

Power and Superintendent’s expenses per ton.0130 

Total.$.0515 

It is often desirable to screen the coal before it is reshipped from 
storage. The screening plant may be carried by the bridge, or it may 
be a separate movable structure. Fig. 41 shows a movable screening 
plant, built by the Link-Belt Company for the Berwind Coal Com¬ 
pany, at Duluth, Minnesota. 

A bridge is also applicable to storing in a circular pile. In such 
a case one end of the bridge is pivoted and the other end moves on a 
circular track about the pivot as a center. Instead of covering a com¬ 
plete circle this bridge may be used to cover any arc of a circle desired. 
A swivel bridge designed to operate in a semi-circle is shown by Fig. 
42. Coal dumped into the pit at the side of the receiving hopper is 
picked up by the grab bucket on the bridge, and placed in storage. 
In reclaiming, the coal is picked up by the bucket, brought back to the 
receiving hopper, and elevated to an overhead storage bin. 

This type of equipment is suited to a much larger storage pile 
and greater handling capacity than the locomotive crane, but is more 
expensive to operate. 

The swivel bridge would probably be less economical than the 
locomotive crane for the handling of quantities within the capacity of 
the latter apparatus but can be advantageously employed for larger 
quantities. Coal may be handled at very little expense by a bridge 
where electric power is available. 

The cost * of swivel bridges abo »^e the rails was given in 1915 as 
from $25,000, for a bridge of 100-foot span, to $50,000, for a bridge 
of 250-foot span; the capacities ranging from one hundred to three 
hundred tons of coal per hour. 


* Proceedings, International Railway Fuel Association, Vol. VII, pp. 159-lCO, 1915. 








Fig. 38. Traveling Bridges oe the Clarkson Coal and Dock Company, 

Duluth, Minn. 



Fig. 41. Movable Screening Plant of Berwind Coal Company 

















THE STORAGE OF BITUMINOUS COAL 


85 


Figs. 43 and 44 show a pivoted bridge built for the Milwaukee 
Coke and Gas Company by the Robins Conveying Belt Company. The 
semicircular concrete track on which the movable end runs has a 500- 
foot radius. The coal is elevated by an enclosed inclined belt conveyor 
which delivers it into a bin in the pivoted-tower (Fig. 43). The coal 
is then put into storage by a belt conveyor, a tripper on the bridge 
depositing it at any desired point in the storage field. It is reclaimed 
by means of a six-ton bucket. 

In order to get as much coal as possible under the bridge, a slight¬ 
ly inclined bulkhead, (Fig. 45) from twenty to twenty-five feet high, 
was built on both sides of the semicircular track and also around the 
outer edge of the pile. This bulkhead is made of boards and timbers 
projecting into the coal pile as shown in Fig. 46. When this method 
of bulkheading was first attempted there was a number of serious 
fires in the pile, probably caused by the circulation of slow currents 
of air through cracks between the planks. This difficulty has been 
overcome by studying the matter of sizes suited to storage and by clos¬ 
ing the cracks, with reference to which J. F. Blackie, superintendent 
of the plant, says: 

‘ ‘ It has been our experience that a coal from two inches up in size allowed a 
flow of air which cooled the pile rather than promoted combustion, and that fine 
coal prevented air circulation and did not, therefore, fire, but wherever the smaller 
lumps accumulated fires started. When all the cracks in the bulkhead were 
plastered with nine parts of coal dust and one part cement, fires were eliminated. ’ ’ 

The Milwaukee Coke and Gas Company has been storing each 
year for the past ten years 400,000 tons in one pile and 250,000 tons 
in another, the coal mixture consisting of 65 per cent West Virginia 
and Kentucky coals averaging 33 per cent volatile and 35 per cent 
Pocahontas averaging 18 per cent volatile. During the summer of 
1917 it also stored Illinois coal in the same manner. 

A method of unloading coal employed by the Canadian Pacific 
Railway at Port William, Ontario, is illustrated by Fig. 47. The 
equipment consists of two Hulett unloaders with buckets of 8 tons 
capacity. The coal is rehandled from the stock pile under the un¬ 
loaders by means of a large bridge, and stored in piles for future 
use. The bridge has a span of 285 feet with cantilevers approxi¬ 
mately 150 feet long, is equipped with a man trolley which handles a 
nine-ton bucket, and is used both for stocking the coal and for re¬ 
claiming. 


86 


ILLINOIS ENGINEERING EXPERIMENT STATION 


33. Deep Reinforced Concrete Storage Bins .—A storage plant 
of unusual design is that of F. W. Stock and Sons of Hillsdale, 
Michigan. It consists of reinforced concrete bins 28 feet in diameter 
and 70 feet deep built in pairs. Hopper bottom cars are unloaded 
through a track grating, the coal is carried by belt conveyor to a 
V-bucket elevator and dumped from the elevator head into the bins. 
A small pocket on the side opposite the elevator leg is used for an¬ 
thracite coal for domestic use. The bins are roofed and the construc¬ 
tion is such as to prevent the free circulation of air (Fig. 48). 

As a precaution against fire each bin has six 1-inch pipes set 
vertically, each pile being open at the top and having three or four 
side openings at intervals. These pipes are connected to a pressure 
water line so that it is possible to fiood the bins if necessary to ex¬ 
tinguish a fire. The bins are designed to withstand the pressure of 
coal having the interstices filled with water. 

The estimated cost of the plant, complete with machinery, is 
$18,000. The capacity is about 2000 tons. Records covering the 
expense of operation are not available, but the opinion is expressed 
that the expense will be less than that of open pile storage, even when 
the interest on the investment is included. 

34. Under-water Storage .—Because of-the liability to spon¬ 
taneous combustion of coal storage piles exposed to the air, under¬ 
water storage has been used to some extent. Thus far this method 
has been applied exclusively to the storage of screenings. 

The consensus of opinion is that coal stored under water deterior¬ 
ates little, if any, in its chemical properties and in heat value. Pro¬ 
fessor Parr* says: 

‘‘Under-water storage prevents loss of heat value and is not accompanied 
by deterioration in physical properties such as slacking. The water retained by 
the coal upon removal is substantially only that held by adhesion or capillarity.’^ 

This opinion is concurred in by a number of other writers,! and 
the opinions expressed in the questionnaire are unanimous upon this 
point. 

At the present time there is a number of under-water storage 
plants and others are under consideration. The general adoption of 

* “Effects of Storage upon the Properties of Coal.” Univ. of Ill. Eng. Exp Sta Bui 
97, p. 7, 1917. ■’ 

t Hall, R. G., Mining and Scientific Press, March 15, 1913; Bennet, A., The Black 
Diamond, April 14, 1917; Palmerberg, W., Proceedings, International Railway Fuel Associa¬ 
tion, May, 1917. 



THE STORAGE OF BITUMINOUS COAL 


87 


under-water storage, however, seems to be influenced by the cost. 
One of the largest elements of cost is that of a suitable storage pit 
which may be an excavation made in solid ground, a dammed de¬ 
pression, an old quarry, or an abandoned clay pit. An abandoned 
quarry or clay pit has the advantage of saving the expense of ex¬ 
cavation hut there may be a considerable item of expense for cleaning 
out the old excavation. A quarry has solid but irregular walls, but 
if these are made even and the quarry cleaned out, it forms an ex- 


Zapacity 500,000 Torts 
46 Acres 



Fig. 39. Parallel Track Storage Yard for a Locomotive Coaling Station 

(Reprinted from the Proceedings of the International Railway Fuel Association) 



Fig. 40. Layout of Storage Yard for Locomotive Coal Station 

(Reprinted from the Proceedings of the International Railway Fuel Association) 


cellent place for storage. A clay pit has the disadvantage of soft 
walls, unless it is lined with timber or concrete. Several c^uarries 
have been used for storage purposes, and apparently with success. 
These old quarries are frequently fed by springs, so that the water 
supply is assured but is generally not sufficient to cause an overflow. 
One of the latest plants has utilized a pit excavated in an old slough 
which has been dredged out. In this case the cost of excavation was 
low and a permanent water supply assured. One drawback to under¬ 
water storage lies in the freezing of the water during winter, or if 
the surface does not freeze the wet coal may freeze while handling. 
So far as reported, however, freezing has not been found troublesome 



















































88 


ILLINOIS ENGINEERING EXPERIMENT STATION 


in the vicinity of Chicago and other Middle West cities near which 
many of the nnder-water storage plants are located. 

A pioneer in under-water storage was the Western Electric Com¬ 
pany, Chicago, Illinois. This company, after a number of fires in its 
bunkers at the Clinton Street plant, built in 1902 a concrete pit with 
a capacity of 3000 tons. It was not water-proof, but the water level 
in the pit was maintained by an intake from the Chicago River. Coal 
was stored in this pit during the winter months and used during the 
early summer without appreciable loss in weight or trouble in burning 
the coal. 

In connection with its extensive new plant at Hawthorne, Illinois, 
the Western Electric Company in 1906 provided a concrete-lined pit 
having a capacity of 10,000 tons. This pit, shown in Figs. 49 and 
50, occupies a ground area of 310 by 114 feet, and is divided into 
three parallel sections by concrete arch partitions. It is about fifteen 
feet deep, and the bottom is inclined since rock was encountered in 
sinking the pit. Water is provided from the roofs of the adjacent 
factory buildings. Three railroad tracks are carried on the arched 
piers and- extend the entire length of the pit, and there are two rail¬ 
road tracks on each side. Coal is unloaded into the pit by hand at an 
expense of five cents per ton. A locomotive crane with a grab bucket 
reclaims and reloads the coal at an expense of about four cents per 
ton. Loaded cars stand on the tracks from twenty-four to forty- 
eight hours to allow the water to drain off into the pit. Illinois screen¬ 
ings of one inch or one and one-half inch size are stored. 

According to The Colliery Engineer,^ the original construction 
cost of a pit of this description was about $7,000, for each thousand 
tons capacity. Later, when the company considered extending the 
plant by building a pit which would hold about 22,000 tons, the cost 
of the extension was found to be about $60,000, including the crane 
and necessary railroad tracks. 

Another pioneer in under-water storage is the Illinois Traction 
Company which has two plants, one at Riverton and another at 
Mackinaw.! The one at Riverton holds approximately 9,000 tons 
and the one at Mackinaw approximately 16,000 tons. The con¬ 
struction of these pits is shown in Fig. 51. The fioor of the pit 
illustrated is 275 feet by 80 feet and the tank is 319 feet by 128 feet. 

* January, 1915. 

t Detailed descriptions of these plants will be found in Electric Railway Journal, April 
1, 1911, and The Colliery Engineer, January, 1915. 



THE STORAGE OP BITUMINOUS COAL 


89 


The water is pumped from the Sangamon River by a motor-driven 
centrifugal pump, and the water in the pit may be drained out when 
desired through a ten-inch valve. The center trestle is of yellow 
pine twenty-four feet high, extends the full length of the pit, and 
rests on concrete with steel rail reinforcing. The floor between the 
trestle bents is also reinforced with rails placed four feet apart. The 
Riverton pit, similar in construction, is twenty feet deep, the bot¬ 
tom being 80 feet by 185 feet and the top 124 feet by 225 feet. The 
concrete bottom has triangular mesh reinforcement instead of rails 
and underneath it are concrete foundations for the bents. The con- 



Fig. 42. Swivel Bridge Designed for Semicircular Pile 

(Reprinted from the Proceedings of the International Railway Fuel Association) 


Crete has a one-inch wearing surface, two per cent of which is a water¬ 
proofing compound. R. J. Carley, chief operating engineer of the 
Illinois Traction System, reported in 1913 that little trouble was ex¬ 
perienced in holding the water in the Riverton pit and that there was 
little deterioration of the coal. There was considerable trouble in 
holding the water in the pit at Mackinaw, and coal in storage there 
for one period of about eighteen months slacked considerably because 
of the lack of water. The difference in tightness was thought to be 
due to the better water-prooflng at the Riverton pit. The Mackinaw 
pit required a small amount of excavation and cost $14,300 or about 
$900 per 1000-ton capacity. The Riverton pit cost $11,000 or about 

















































































90 


ILLINOIS ENGINEERING EXPERIMENT STATION 


$1,225 per 1000 tons. The Kiverton pit was situated so that it was 
necessary to build only earth embankments to hold the concrete re¬ 
taining walls. 

The Illinois Traction Company stores coal of all sizes from the 
Worden district, Illinois, and keeps it in storage for from six months 
to three years. There is no appreciable loss in heat value, and there 
is no appreciable breakage. The total expense of operating these 
plants is 14.6 cents per ton for storing and 7.8 cents for reclaiming. 
The Company also stores coal upon the ground in continuous piles 
fifteen feet deep and in case of heating removes the coal from the 
affected spot. 

The American Zinc Company of Illinois stores 35,000 tons in a 
lake at its Hillsboro plant, the coal being dropped into the water 
through a plate girder bridge, and reclaimed by a centrifugal pump 
which delivers it into a dewatering elevator. The coal keeps in ex¬ 
cellent condition under water and contains practically no more 
moisture when reclaimed than when freshly mined. The company 
also carries a stock of from thirty to forty cars of coal which lies on 
the ground for not more than thirty days. According to A. Ives, 
Superintendent, coal stored in the open deteriorates so rapidly that 
it is almost useless for gas making. 

The East St. Louis Light and Power Company cleaned out an 
old rock quarry adjacent to its power station in which about 7,000 
tons of coal are stored under water. This plant has been operating 
satisfactorily except for some slight difficulty due to freezing in the 
winter. There is also some difficulty due to freezing in the bunkers. 

The National Zinc Company of Springfield, Illinois, utilizes an 
old clay pit about 250 feet wide, 450 feet long, and 45 feet deep 
which has a capacity of about 30 car loads.* This pit formed a 
natural sink in the surrounding prairie, and was, therefore, usually 
filled with water to a point about five feet from the top. The sides 
and bottom are of comparatively hard shale. A railroad track paral¬ 
lels the longer side. The track is carried on a low trestle over an un¬ 
loading chute, sufficiently wide to accommodate one car. The bottom 
of the chute has a slope of ten per cent toward the pond, and the out¬ 
let into the pond is about four feet wide. At the top end of the chute 
is a ten-inch pipe having four-inch holes in the side. This pipe is 
attached to a ten-inch centrifugal pump which delivers about 3,500 

* Detailed description of this plant will be found in Mining and Scientific Press, p. 406, 
March 15, 1913 and in The Colliery Engineer, p. 299, January, 1915. 




Fig. 43. Pivoted Bridge of the Milwaukee Coke and Gas Company 





































Fig. 44. View Looking toward Pivoted End, Bridge of the Milwaukee 

Coke and Gas Company 

















Fig. 45. Bulkhead at the Storage Plant of the Milwaukee Coke and 

Gas Company 



Fig. 46. View Showing Construction op the Bulkhead at the Plant of the 

Milwaukee Coke and Gas Company 







Fig. 47 . Hulett Unloaders of the Canadian Pacific Eailway at 

Fort William, Ontario 




















































Fig. 48. Reinforced Concrete Storage Bins of F. W. Stock and Sons, 

Hillsdale, Michigan, Designed and Built by Macdonald Engineering 

CoMPANY^, Chicago 









Fig. 49. View of the Under-water Storage Pit of the Western Electric 

Company at Hawthorne, Illinois 



Fig. 50. View of the Under-water Storage Pit of the Western Electric 

Company at Hawthorne, Illinois 












Fig. 52. Storage Pit of the New Kentucky Coal Company, Kankakee, 

Illinois 



Fig. 53. Concrete Storage Pit of the Indianapolis Light and Heat 

Company 













Fig. 54. Storage Pit of the Metropolitan Water District of Omaha 





Fig. 55. Storage Pit and Bridge of the Western Clock Works 


THE STORAGE OF BITUMINOUS COAL 


99 


























































































































100 


ILLINOIS ENGINEERING EXPERIMENT STATION 


gallons per minute. When a loaded car is placed on the trestle, two 
men open the drops, section by section. This action throws most of the 
coal into the chute, and the water backs into the chute until the ac¬ 
cumulation is sufficient to move the whole mass of material. When 
the bulk of the material has moved out, the men close a valve in the 
pipe to the chute, and throw the whole stream of water directly into 
the car to clear it. The whole operation of unloading a car requires 
on the average about ten minutes. 

In reloading, the coal and water are pumped directly into the 
elevator boot which is placed in a hopper-shaped hole excavated in 
the ground and lined with plank, and the water is forced to travel 
slowly around the hopper before finding its way back into the pond. 

The coal pump is placed on a barge 15 feet by 40 feet and is 
belted to a 50-horse-power motor. Both the suction and discharge 
are light spiral riveted iron pipes, which though short lived provide 
ease of its manipulation. The discharge pipe is carried on pontoons 
made from oil barrels. One operator on the barge finds no difficulty 
in moving the pipe around as the ground is worked out. 

J. Kaercher, of the National Zinc Company, reports that the 
expense of storing at present is ten cents per ton and the expense 
of reclaiming ten cents per ton. The coal is kept in storage indefin¬ 
itely and different sizes are stored without being separated. The 
coal stored is to be used for the production of producer-gas, and there 
has been no appreciable deterioration. 

The New Kentucky Coal Company at Kankakee, Illinois, has a 
complete under-water storage plant, built according to the plans of 
Mr. Harwood, its vice-president and general manager. An old lime¬ 
stone quarry was utilized as the storage pit, the water being supplied 
from springs which keep the quarry full. The shape of the basin is 
elliptical, being about 700 feet long, 310 feet wide, and 30 feet deep. 
Since the rock was channeled, the sides are in excellent shape and are 
regular. A view of this pit is shown as-Fig. 52. Water obtained 
from pipes along the track is used to flush the coal out of the cars 
and down the chute into the pond. As the coal piles up around the 
bottom of the chute, it is pumped out into the quarry by means of a 
ten-inch centrifugal pump operated by a 75-horse-power motor, the 
pump and the motor being mounted on a barge. The pipe line con¬ 
sists of a sectional pipe, ten inches in diameter, which rests on 
pontoons. 


THE STORAGE OF BITUMINOUS COAL 


101 


To reclaim the coal the process is reversed and the coal is pumped 
from the quarry into the concrete pit at the base of the inclined 
elevator. When this pit is filled with coal, the water overflows back 
into the quarry. Coal from the pit is elevated by a flight conveyor 
of perforated buckets through which much of the water drains and 
is delivered into cars on the railroad track. In the small house at the 
left of the elevator (Fig. 52) is a six-inch centrifugal pump operated 
by a 25-horse-power motor which pumps the water needed for flushing 
the coal from the cars and down the chutes. The storage capacity is 
estimated to be from 200,000 to 250,000 tons of coal and it is stated 
that about 2,000 tons per 8-hour day can be unloaded and 1500 tons re¬ 
claimed. Coal of sizes under three inches can be handled by the equip¬ 
ment. Unfortunately, the plant has not been operated owing to lack of 
coal supply. Three men are required to operate the plant and the cost 
IS estimated to be from seven to ten cents per ton for unloading and 
reclaiming. The equipment cost about $20,000, including the switch 
track and trestle, but at the present time the same equipment would 
cost from $28,000 to $30,000. 

The Indianapolis Light and Heat Company (T. H. Wynne, Su¬ 
perintendent of Power) stores 20,000 tons of Indiana run of mine 
coal from the Linton district under water in concrete tanks twenty- 
four feet deep (Fig. 53). The coal is dumped directly from railroad 
cars and is reclaimed by a locomotive crane. A deterioration of less 
than three per cent in heating value is said to take place. The stored 
coal is used after the first of January, when the price of coal is, 
normally, highest, and the pit is refilled during March, April, 
and May. 

The Metropolitan Water District of Omaha, Nebraska, stores 
for steam purposes 4,000 tons of Iowa, Kansas, and Illinois coals. 
Most of this is slack below three-fourths inches, although some nut 
and washed coal is used. The storage pit (Fig. 54) is of concrete ten 
feet deep. The period of storage is about six months. The coal 
is piled from fifteen to twenty feet above the water in order to 
get an additional storage. This coal may heat in from 
three days to two months and if so it is then turned over by means 
of a locomotive crane which is used to stock and unload the coal 
from the bins. 

*See Electrical World, Vol. 62, p. 592, Sept. 20, 1913, Electric Railway Journal, 
Vol. 42, p. 391, Sept. 6, 1913, Engineering News, Vol. 70, p. 527, Sept. 1, 1913, Power, 
Vol. 38, p. 485, Sept. 30, 1913. 



102 


ILLINOIS ENGINEERING EXPERIMENT STATION 


The expense of this storage is given as follows: 



Storing 

Reclaiming 

Overhead. 

. $0,003 

$0,003 

Labor. 

.012 

.012 

Supplies. 

.005 

.005 

Depreciation on mechanical equipment . 

.024 

.024 

Interest on investment. 

.019 

.019 

Total. 

. $.063 

$.063 

The Company also stores some coal 

on the ground, but because 


of fires is now planning to store 30,000 additional tons in abandoned 
concreted water basins, utilizing a hydraulic ejector similar to those 
used for years in transporting sand through a pipe for filtration pur¬ 
poses. G. T. Prince, Chief Engineer, says: 

“Any coal stored in the air, whether supported by coal in a pit under water 
or by planking on the ground is subject to spontaneous combustion. This is par¬ 
ticularly true of coal received in a damp, wet state. When such coal reaches us 
we exercise great care in watching it, as it is sure to catch fire within a few weeks 
and possibly within a few days. Coal received during the dry summer days will 
be free from combustion for several months. “ 







00 - 0 ^ 


Fig. 51. Coal Storage Pit op the Illinois Traction Company at 

Mackinaw, Illinois 


























































































THE STORAGE OF BITUMINOUS COAL 


103 


Fig. 55 shows a cross-section of a storage pit recently built by 
the Western Clock Works in Peru, Illinois. The pit is 87 feet long, 
46 feet, 3 inches wide, and 13 feet deep and has a capacity of 1200 
tons under water. The cost of the plant was $15,300. The coal stored 
comes from a mine, about two hundred feet distant. The traveling 
bridge and bucket are used to distribute the coal in the pit and to 
reclaim it. The reclaimed coal is placed in the small cars on alternate 
days, the cars being allowed to drain, for a day before the coal is 
delivered to the boiler room. 

One of the largest under-water storage plants now under con- ^ 
struction is being built by the Great Lakes Dredge and Dock Company 
for the Standard Oil Company of Indiana at Whiting, Indiana. The 
pit will be 1000 feet long, 202 feet wide below the ground water level, 
and 26 feet below the yard rail level. The system is to be practically 
the same as that of the Western Electric Company at its Hawthorne 
plant but instead of the heavy concrete construction for walls and 
trestles, wood piles will be used below water level and will be capped 
with a coping of concrete above water level. The bottom of the pit 
will be roughly graded and lined with concrete one foot thick. The 
only part of the construction which will be subject to deterioration 
will be the ties, stringers, and caps of the railroad trestle which are 
above water. 

Four trestles, on which will be a standard gage track, will ex¬ 
tend from end to end of the pit. Alongside the pit will be two rail¬ 
road tracks, so that locomotive cranes to be used for reclaiming may 
operate from the trestles above the pit or from the side tracks. It 
is estimated that the cost of construction will be much less than that 
of the concrete types used in other plants. By means of the four 
tracks placed on the trestles and the two on the sides, six trains may 
be unloaded at one time. 

The Peabody Coal Company of Chicago has three under-water 
storage plants, one holding about 80,000 tons at Kankakee, one hold¬ 
ing 60,000 tons at Lemont, and another at Momence, Illinois. The one 
at Momence, however,’has not been placed in operation. In each case 
an old quarry has been used. The coal is dumped into the quarry 
from a track running near the edge and distributed by means of a 
centrifugal pump. In reclaiming, the coal is pumped into an ele¬ 
vator and delivered directly into railroad cars. The Company reports 
that where the pile of coal projected above the water level along the 
bank it took fire. 


104 


ILLINOIS ENGINEERING E:JiPERIMENT STATION 


An estimate given by the engineers of the Peabody Company for 
the cost of equipment and the expense of operation of the Lemont 
plant is as follows: 

Estimated Cost op Equipment at Lemont Storage 
(Based upon handling 700 tons of coal per day—allowance made for 

STOPPAGE AND BREAKDOWNS) 

Shooting rock and building unloading chute.$350.00 

Building concrete piers, laying stringers, and installing track . 780.00 

Eearrangement of track to get greater capacity. 800.00 

12-inch centrifugal pump, directly connected to 100-horse-power 

steam engine. 2250.00 

Boat to float pump and engine. 600.00 

300-foot spiral riveted pipe with bolts and gaskets .... 800.00 

2- to 5-foot sections of rough bore suction and 

2- to 5-foot sections of smooth bore discharge hose .... 800.00 

125-horse-power self-continued steam boilers. 1000.00 

Priming pump, connected to pump engine, 12-inch check valve . 125.00 

Steam injector, boiler fittings, etc. 225.00 

100 feet of 3-inch steam pipe and 3-to 5-foot sections of 3-inch 

steam hose.110.00 

Elevator of dewatering type, to elevate 120 tons of coal per 

hour at a speed of 50 feet per minute, connected to steam 

engine. 2000.00 

Wood receiving boat at foot elevator 20 by 20 by 8 feet, also 

wood support and erection of elevator. 700.00 

Self-contained car puller and engine with 1500 feet of p^-inch 

steel cable, with head sheaves, etc. 650.00 

Eopes, blocks, bars, etc. 200.00 

10 per cent for supervision.1140.00 


Total.$12,530.00 

To clean quarry: 

Pumping dry, removing debris from bottom, and additional 

expenditure estimated.$1500.00 














THE STORAGE OF BITUMINOUS COAL. 


105 


Estimated Expense of Operation at Lemont Storage 
(Based upon handling 700 tons ob' coal per ten-hour day) 


Unloading 

Per Day 

Expense Per Ton 

Superintendent (1). 

. $5.50 


Pumpman (1). 

. 3.50 


Carpuller (1). 

. 3.00 


Dumpers and Pipemen (2) . 

. 6.00 


Fuel for boilers and lubricating oil . 

. 6.00 


Miscellaneous repairs and supplies . 

. 2.50 


Night Watchman (1) . 

. 3.00 


Total . 

$29.50 

$0,042 

Eeloading 

Superintendent (1). 

. $5.50 


Pumpman and Helper (1) 

. 6.50 


Pipeman (2). 

. 6.00 


Trimmer (1). 

. 3.00 


Carpuller (1). 

. 3.00 


Fuel for boiler, oil, etc. 

. 6.00 


Miscellaneous supplies and repairs 

. 2.00 


Night Watchman and Trimmer (1) . 

. 3.00 


Total . 

$35.00 

$0.0500 

6 per cent per annum on investment* 

$15,000 spread over 60,000 tons = $900* . 

. . . 0.0150 

Unforeseen delays, etc.*. 

Losses one per cent on 600 tons at $1.50 


. . . 0.0100 

per ton — $900*. 


. . . 0.0150 

Depreciation on equipment* .... 


. . . 0.0200 

Accident insurance, etc.*. 


. . . 0.0100 

Total Expense of Storing 

. . . $0.1620 


If electric power is used, the cost will be five cents per ton higher. 

The following are comparative estimatesrof the^xpense of under¬ 
water and surface storage made by C. G.^Hall, forkierly fuel agent 

of the C. & E. I. Eailroad. ; 

— 

* Bosses at one per cent are estimated upon the Ibasis of operation over a period of 
years. The interest, delays, depreciation, and similar expenses are based upon loading 
and unloading 60,000 tons per annum. A smaller tonnage will materially increase these 
items of expense. 




















106 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Storage of Screenings (Indiana Coals) 

Subaqueous Storage (3rd, 

5th, and 6th vein coal) . . 100,000 Tons 

Pump outfit.$12,000.00 

Interest and depreciation . . 20 per cent $2,400.00 

Tracks (estimated). 2,000.00 

Interest and depreciation ... 15 per cent 300.00 

Labor, supplies and power, 

Unloading and reloading. 10,000.00 

Eental of storage pit.I . . . . 250.00 

Value of 100,000 tons at 50 
cents per ton and freight 
charges at 82 cents .... $132,000.00- 

Interest on $132,000.00 

at 6 per cent for 8 months. 5,280.00 

$18,230.00 

Average per ton.18.23 cents 

Surface Storage (4th Vein Coal) . . 25,000 Tons 

Locomotive crane.$8,000.00 

Interest and depreciation ... 20 per cent $1,600.00 

Tracks. 5,000.00 

Interest and depreciation ... 15 per cent 750.00 

Labor and supplies. 

Unloading and reloading. 2,500.00 

Rental of ground, etc. 200.00 

Value of 25,000 tons at 75 cents 
per ton and freight charges 
at 77 cents per ton.$38,000.00 

Interest on $38,000.00 for 8 months 

at 6 per cent. 1,520.00 

$6,570.00 


Average per ton on 25,000 tons . . 26.28 cents 











THE STORAGE OF BITUMINOUS COAL 


107 


VI. Effects of Storage upon the Properties of Coal 

The effects upon the properties of coal may he considered under 
the following heads: 

(1) Appearance. 

(2) Loss of heating value. 

(3) Firing qualities. 

(4) Spontaneous combustion. 

(5) Coking and gas making properties. 

(6) Degradation, or the increase in the amount of fine coal 
and dust due to breakage from handling, and to slacking or 
weathering. 

(7) Loss in weight. 

35. Appearance. —Many coals upon exposure to the air become 
covered with a coating of white iron sulphate which causes a pile to 
look as though covered with frost. This white coating is thought by 
many to signify deterioration of the coal, but as shown by Professor 
Parr it merely signifies that some of the sulphur has oxidized to the 
white sulphate, which is soluble in water, and is easily washed away 
by rain. The ash content of such coal is also slightly lower than that 
of fresh coal. In any case, the white coating is only a covering, and 
the coal below the surface of the pile is not affected. 

36. Loss of Heating Value. —The loss of heating value resulting 
from storage is comparatively small and Parr^' says with regard to 
this: ‘ ‘ Bituminous coal can be stocked without appreciable loss of 
heat values provided the temperature is not allowed to rise above 180 
degrees P. In fact, there is no appreciable evolution of CO 2 at tem¬ 
peratures below 260 degrees P. The indicated heat loss per pound of 
coal is due more largely to an increase in weight of a unit mass of 
coal resulting from the absorption of oxygen rather than from an 
actual deterioration or loss of heat units. . . . Under-water storage 
prevents loss of heat value.” According to detailed values given by 
Parrf and summarized in Table 5, the indicated loss of heating value 

* “Effects of Storage Upon the Properties of Coal.” Univ. of Ill. Eng. Exp. Sta., 
Bui. 97. pp. 7. 38. 1917. 
t Ibid., pp. 15-22. 



108 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Table 5 

Decrease in Heating Value (B. t. u.) of Illinois Coals 



Nut 

Screenings 

Nut 

Screenings 

Coal Tested and 
Length of Time Stored 

Exposed 

Bins 

Covered 

Bins 

Exposed 

Bins 

Covered 

Bins 

Under¬ 

water 

Under¬ 

water 


Per cent 

Per cent 

Per cent 

Per cent 

Per cent 

Per cent 

Stored 1 year 







Williamson County. 

0.84 

1.64 

1.37 

1.35 

0.93 

0.57 

Vermilion County. 

2.13 

2.77 

. 3.92 

4.46 

2.00 

2.72 

Sangamon County. 

3.15 

4.12 

5.14 

4.52 

1.83 

0.86 

Stored S years 







Williamson County. 

2.09 

3.60 

2.11 

3.73 

.... 

.... 

Vermilion County. 

4.98 

6.23 

8.48 

10.47 

.... 

.... 

Sangamon County. 

4.54 

... * 

7.11 

10.48 

.... 

.... 

Stored 6 years 







Williamson County. 

3.04 

3.60 

3.96 

4.31 

.... 

.... 

Vermilion County. 

5.49 

6.39 

10.83 

.... 

.... 

.... 

Sangamon County. 

6.49 

6.81 

6.85 

10.81 

.... 

.... 


after a period of one year in storage is relatively low, averaging for 
nut coals and screenings from Williamson, Sangamon, and Vermilion 
counties only about 3 or 3^ per cent. Coals vary in this respect, 
those from southern Illinois showing less change than those from 
central Illinois and this difference increases with the length of time in 
storage, that is, the coals which show a small decrease in heating value 
at first continue to show a relatively small decrease as time goes on. 

Decrease in heating value is consistently greater with screenings 
than with screened nut, according to Parr’s tests of Illinois coals. 

Coal stored in open bins shows consistently a lower percentage 
of loss of heating value than coal stored under cover, due no doubt 
to the oxidation of the sulphur when exposed to the air and its sub¬ 
sequent leaching out. 

Experiments made by the Bureau of Mines upon large samples 
of coal gave the following results 

^‘The amount of deterioration of coal in heating value during storage has 
commonly been overestimated. Except for the subbituminous Wyoming coal, no 
loss was observed in outdoor weathering greater than 1.2 per cent in the first 
year, or 2.1 per cent in two years. The Wyoming coal suffered somewhat more 
loss; 2 to 3 per cent in the first year and as much as 5.5 per cent in three years.’’ 


* Porter, H. 0., and Ovitz, F. K., “Deterioration in the Heating Value of Coal Dur¬ 
ing Storage.” U. S. Bureau of Mines, Bui. 136, p. 8, 1917. 



























THE STORAGE OP BITUMINOUS COAL 


109 


New River coal tested at Portsmouth, N. 11., Pittsburgh, Pa., 
and Norfolk, Va., gave the following results: 

“In general, the conclusion to be drawn from these tests is that New Kiver 
coal, under severe conditions of outdoor exposure to the weather, deteriorates in 
heating value approximately one per cent in the first year, two per cent in the 
first two years, and not over three per cent in five years. Storage under water pre¬ 
vents practically all deterioration during one year, and no more than 0.5 per cent 
has been found in any test for two years or less. Salt water possesses no ad- 
\antage over fresh water in preventing deterioration. Intermittent exposure and 
partial drying of the submerged coal probably causes deterioration in some degree, 
although very small. 

“Submergence storage of New Eiver coal is not to be recommended for the 
sake of preventing deterioration in heat value. Its advantage lies only in in¬ 
suring against spontaneous combustion. ’ ’ * 

Tests of Pittsburgh coal at Ann Arbor, Mich., gave the following 
results: 

‘ ‘ The amount of deterioration in one year’s open air storage was practically 
negligible, even in the upper six inches of the exposed coal. During the second, 
third, fourth, and fifth years the deterioration proceeded very slowly and did not 
reach an amount greater than 1.1 per cent in five years. The submerged portions 
may be said to have suffered practically no loss measurable by the degree of ac¬ 
curacy used. ’ ’ t 

Pocahontas coal tested on the Isthmus of Panama gave the fol¬ 
lowing results: 

“During one year’s outdoor exposure this coal deteriorated very slightly 
(less than 0.4 per cent) in heating value, and that the deterioration took place 
entirely during the first months (June 15 to December 15). There was a further 
deterioration of 0.4 per cent during the second year.” X 

Sheridan, Wyoming, lignitic coal stored at Sheridan gave the 
following results: 

“Coal under the conditions of these tests loses 3 to 5.5 per cent of its heat 
value in about three years’ storage, the greater part (70 to 80 per cent) of this 
loss being in the first nine months. During the period of 2^ years, the deep bins 
suffered the greatest loss, probably because their sides offered greater surface for 
access of air than those of the small bins. The latter became covered with a 12-inch 
layer of fine slack that helped to protect the layers beneath from oxidation. In 
the deep bins, the lumps became badly cracked, but retained their form sufliciently 
to give more ready access of air, and thus permit greater oxidation. 

‘ ‘ In storage of Sheridan coal for more than three months, covering the bins is 


* Ibid., p. 22. 
t Ibid., p. 25. 
t Ibid., p. 29. 



no 


ILLINOIS ENGINEERING EXPERIMENT STATION 


not as advantageous as the use of air-tight bottoms and sides (of concrete, for 
example), and the accumulation of a protecting layer of fine slack on the surface. 
The deterioration of Sheridan coal in heat value can probably in this manner be 
kept below three per cent in one year, and will probably not increase to more than 
four per cent in two or three years if the coal remains undisturbed. Physical 
deterioration (slacking) is also largely prevented in the under portions by the 
formation of a closely packed layer of slack, at least twelve inches thick on the 
surface. 

‘ ‘ Although no indications of spontaneous heating were noted in the tests here¬ 
in described, it is found in practice to be dangerous, on account of dangerous heat¬ 
ing, to store Sheridan coal in piles greater than about ten feet in depth or width. 
In large masses of coal radiation of spontaneously developed heat is restricted to 
a dangerous degree. Submerged under water would probably prove particularly ad¬ 
vantageous as a means of safely storing subbituminous coal of the Sheridan 
type’ 

The Coal Storage Committee of the International Railway Fuel 
Association in 1915 reported that for Ohio, Pennsylvania, and West 
Virginia the loss was very slight and that no difference was noted by 
customers of a large coal company between the fresh coal and coal 
stored from six to twelve months. 

The Boston and Main Railroad has had coal in storage from 
fifteen to twenty years with no signs of heating, and although there 
was surface deterioration, lumps were found within the pile which 
looked like freshly mined coal and showed a heat value of 13,000 
B. t. u. 

Kansas coal showed a shrinkage of 5.26 per cent in weight due no 
doubt to drying out. 

Oklahoma, Kansas, Missouri, and Northern Arkansas coals lose 
from two to eight per cent in heating value and Texas coals much 
more due to spontaneous combustion. 

J. G. Crawford, Fuel Engineer of the C. B. & Q. R. R., says: 

‘‘In general, the deterioration of coal stored in piles will be less as the dis¬ 
tance from the surface increases. Thus the total amount of deterioration per ton 
of coal depends upon the width and depth of the pile. If we have a pile only five 
or six feet deep, as sometimes happens when coal is stored hastily without any de¬ 
fined system, the total aniount of the deterioration per ton is going to be a great 
deal more than if the pile were twenty (20) feet deep, because in the smaller pile 
the area of exposed surface per ton is a great deal more than in'the case of the 
larger pile. 

“We stored a Wyoming bituminous coal, which was 10 per cent moisture, 16 
per cent ash, 5 per cent sulphur and 11,000 B. t. u. This coal was in a pile twenty 
feet deep and fifteen feet broad on top. At the end of four years it was found that 


* Ibid., pp. 33-34. 



THE STORAGE OF BITUMINOUS COAL 


111 


there had been no deterioration in this coal when a point about three feet below 
the surface was reached. The major portion of the deterioration was in the coal 
forming the flat top, which allowed the rain and snow to collect, no means being 
provided to shed the rain and snow. ’ ’ 

The Consolidation Coal Company Fairmont, W. Va., reports no 
changes in the chemical properties of coal and less than to 1 per 
cent loss of calorific value after storing a 200-ponnd sample for a 
period of eighteen months. 

The Westmoreland Coal Company of Irwin, Pa., says: 

‘ ‘ This company has made some elaborate tests of the storage coal and 
weathering, and the results have shown that there is a very unexpectedly slight 
deterioration; that is to say, at least, in our coal. The coal pile oxidizes rapidly on 
the outside and puts on an overcoat of slack or fine coal, which seems to protect the 
interior of the pile and this process of greater or less oxidation and slacking goes 
on to a depth of, say, twelve inches or thereabouts, and underneath that we have 
generally found all its original value. Indeed, in some tests we have found that 
there has been no deterioration, even in the much more delicate tests of gassifica- 
tion and production of illuminating gas. We have had some coal exposed in piles, 
and some under cover, for some ten or fifteen years, and the general reply to your 
inquiry would be that there is no material depreciation. ’ ’ 

It is difficult to differentiate between losses in storage piles due 
merely to natural weathering and those due to incipient or actual 
spontaneous combustion of the coal, also between losses in heating 
value and losses in coking and gas making or other properties. An 
effort was made to obtain information upon these points through 
the questionnaire, but it has not always been possible to interpret 
correctly the exact meaning of the answers upon these closely re¬ 
lated subjects. The answers received to Question 13 of the Question¬ 
naire, ‘‘Does the coal decrease in heating value as a result of stor¬ 
age?” were, “Yes,” 21, and “No” or “Not appreciably,” 20 and 
“Very little,” 2. The percentages of depreciation given were less 
than 5 per cent in six cases, between 0 and 10 per cent in three, from 
10 to 20 per cent in one, and from 20 to 50 per cent in one. The 
lower percentages probably express the same general opinion as 
“Very little” or “Not appreciably,” and it is evident that the higher 
percentages mean after heating takes place. 

These opinions, based mainly upon observation and experience 
in storing large amounts of coal under various conditions though not 
upon calorimetric or boiler tests, agree in general with the results of 
the tests of Parr, Porter, and Ovitz upon comparatively small sam- 


112 


ILLINOIS ENGINEERING EXPERIMENT STATION 


pies or test lots, that is, that the loss in heating value due to storage 
alone is small and should not deter any one from storing coal through 
fear of any financial loss due to a decrease in heating value. 

The most adverse opinion, but an interesting one, was given by 
A. Geschwindt, General Manager of the Eockford Electric Company, 
who says: 

‘^Our experience has been that through the heating of the coal and therefore 
drying out, we lose considerable efficiency. If there is some method used whereby 
the moisture could be returned to the coal that is dried through heating, we could 
obtain results from this coal with less loss than we do at the present time. This is 
aside from that part of the coal which is actually burned while in storage pile.. 

‘ ‘ I have not been in a position to make actual tests other than laboratory tests 
on the value of coal that has been heated thoroughly in storage piles, but we find 
that in the ordinary course of burning the coal under boilers we get only half the 
efficiency of the boiler therefrom. While on the other hand, from testing in the 
laboratory we find that the coal shows not to exceed ten per cent loss. 

‘^This is the difference between actual test of coal through the laboratory 
method and that of burning in the ordinary course of firing for steam.” 

37. Firing Qualities .—There is a general opinion among fire¬ 
men that stored coal is dead, and burns less freely than fresh coal. 
It is often condemned by them as being ‘‘no good.” Others state 
just as strongly that it burns better than fresh coal, but it seems to 
be the opinion of those who have given most careful thought to the 
matter that although there is no material depreciation in heating 
value, some coals at least, probably due to the loss of a small amount 
of volatile material, do not burn so freely after storage and must be 
fired in a slightly different manner. 

Melvin Patterson, of the Brown Hoisting Machinery Company, 
Cleveland, Ohio, says: 

^^Ohio, Pennsylvania, and West Virginia bituminous coal stand the weather 
conditions best. The coals are piled forty and fifty feet high along the lakes. The 
danger due to spontaneous combustion, provided the coal is placed in the pile 
properly, is very slight. With the modern large grab bucket machines deteriora¬ 
tion due to spontaneous combustion is cut to a minimum as the grab bucket can 
dig around the fire in less than twenty-four hours. Large operators say if they 
can get the coal pile off the dock in one year deterioration is negligible. ’ ’ 

The Fuel Station Committee of the International Eailway Fuel 
Association concludes with regard to different coals: 

‘‘No serious consideration need be given to the question of deterioration, but 
each coal should be carefully studied to determine the best methods for preventing 


THE STORAGE OF BITUMINOUS COAL 


113 


spontaneous combustion and it is advisable to store coal from different fields in 
separate piles. ’ ’ 

In connection with the six-year weathering tests* of southern 
and central Illinois coal, samples of nut coal from Sangamon, Ver¬ 
milion, and Williamson counties and screenings from Sangamon and 
Williamson counties were tested under a boiler by A. P. Kratz.f He 
states: 

‘^On the first test the coal banked slightly at the water-back, and the whole 
amount on the grate became clinkered. It immediately became evident that in 
order to run at all, the coal had to be kept away from the water-back. After the 
clinker had been removed, a fresh start was made and care was taken to keep the 
fuel bed from four to six inches away from the water-back. When this was done 
no further trouble was experienced. ’ ’ 

The tests showed that weathered coal requires a stronger draft 
than fresh coal, indicating that although the weathered and fresh 
coals have approximately the same B. t. u. values, weathered coal is 
more sluggish in action. 

The general summary covering the behavior of the coal in steam 
generation after six years of storage, according to Kratz,J is as fol¬ 
lows : 

‘‘1. Burning weathered coal is largely a question of correct hand¬ 
ling and ignition. Under these circumstances it gives as good results as 
fresh screenings. 

“2. Weathered coal requires a little thinner fire and more draft than 
fresh screenings. 

‘^3. When using weathered coal the fuel bed should not approach 
any nearer to the water-back than from four to six inches, otherwise 
trouble with clinker is experienced. 

‘‘4. Practically as high capacity was obtained with weathered coal 
as with other coals used, and, if anything, the fuel bed requires less at¬ 
tention. ’ ’ 

These conclusions refer to burning stored coal under a stationary 
boiler where the draft can be much more easily regulated than in loco¬ 
motive firing. If coal has become broken in storage and is burned in 
a locomotive, there will be an additional loss through the fine coal being 
carried out the stack. 

Interesting information about coal exposed to the air for a long 
period has been furnished by John J. Davies, Commissioner of the 

* Parr, Op, Cit., p. 36. 

t “A Study of Boiler Losses.” Univ. of Ill. Eng. Exp. Sta., Bui. 78, p. 50, 1915. 
t Op. Cit., pp. 53-54. Note .—Attention is particularly called to the opinions upon 
this subject given in Appendix II, p. 132. 



114 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Saline County Operators Association, and A. W. Helmholtz, of the 
Continuous Process Coke Company of Harrisburg, Illinois. In De- 
Koven, Union County, Kentucky, there is a pile of approximately 
30,000 tons of coal, mostly slack and supposed to have been dumped 
where it now lies between the hills some forty or fifty years ago. 
When the samples were taken, the lower part of the pile was saturated 
with water, but the pile had previously been subjected to weather 
conditions. Tests of this coal made by Helmholtz gave 9.4 pounds 
of water evaporated per pound of raw coal as compared with 10.3 
pounds of water per pound of Saline County slack. The B. t. u. 
values calculated from analyses gave 11,000 as compared with about 
13,500 for fresh coal presumably from the same seam and locality. 

38. Spontmieoiis Conibustion .—The greatest difficulty in the 
storage of coal is undoubtedly the tendency of many coals to fire spon¬ 
taneously. As previously mentioned it is the deterioration due to 
this cause which is often confused with a supposed decrease of heating 
value as a result of storage. 

The gradual heating of a coal pile is due mainly to slow oxidation 
of the carbon in the coal and, to a less extent, to the oxidation of 
the sulphur in the iron pyrites contained in the coal. If the air 
supply is sufficient to permit oxidation but not sufficient to carry 
away the heat as rapidly as it is formed, the temperature in the pile 
will rise gradually and finally the coal will fire. Any method of stor¬ 
age to be successful must be so designed that the heat generated in the 
pile will not exceed the heat lost by radiation. Freshly mined coal has 
a special tendency to oxidize and thus to heat. While this property 
varies with different varieties of coal, it is generally true of all coals. 
The greater the time elapsing between the mining and storing of any 
coal, the less is the liability to firing; hence, if possible, coal should be 
exposed to the air, that is, allowed to become seasoned before it is put 
in storage. This is, of course, frequently impracticable. 

Oxidation of both the carbon and the sulphur takes place more 
rapidly as the temperature increases; hence coal stored during hot 
weather is more likely to heat than that stored on cool days. In spite 
of this fact, however, many prefer to store coal during July and 
August not only because of the lower price which usually prevails 
during these months, but because, as they say, ‘‘the coal is drier and 
less apt to fire.” 


THE STORAGE OF BITUMINOUS COAL 


115 


The smaller the coal the greater is the surface area exposed to 
the air, the more rapid is the oxidation and the greater the tendency 
to heat; hence coal in lumps is not so likely to fire as fine coal, slack, 
or run of mine coal. If possible, the slack should be removed before 
storing. Great care, therefore, should be taken in handling the coal 
to minimize the breakage. In handling large quantities of coal this 
precaution cannot be given the same attention as when handling small 
quantities, but whenever it is impossible to screen the coal before stor¬ 
ing and whenever sizes and kinds must be mixed, -means should be 
provided to open the pile rapidly since heating may then be expected. 
Many persons believe that washed coal will not fire so readily as un¬ 
washed, because the dust has been removed. 

Air currents through a pile, unless ample to carry off the heat, 
should be avoided since many fires seem to be due to sluggish air 
currents in contact with fine coal. Coal should, when possible, be 
piled to avoid alternate stratification of coarse and fine coal. 

The opinion is wide-spread that a mixture of different varieties 
of coals is more liable to spontaneous combustion than a pile of a 
single variety, and while no explanation of this opinion has been given 
it is possible that the most easily combustible coal in a pile merely 
starts the heating and thus lowers the safety point of the less com¬ 
bustible coal. J. B. Porter says: 

^‘With reference to the prevailing opinion that a pile of mixed coal is more 
liable to heat than one of uniform material: I can only say that my observations 
so far as they go bear out this opinion, but do not throw any clear light on the 
case. I can see no reason why a mixture of coals should be any worse than the 
worst coal in the lot, and I think it quite likely that this will prove to be true. 
There are, however, so many authenticated cases of mixed coals heating when ap¬ 
parently either of them would have kept safely by itself that I think we should 
keep on the safe side by avoiding mixtures whenever possible. I may add that 
the objection to mixtures is by no means confined to this continent; in fact if my 
memory serves me the danger of coal mixtures was first pointed out in England, 
and I believe in connection with Easd Yorkshire coals. 

A high percentage of volatile matter in coal does not of itself 
increase its liability to spontaneous combustion. As a result of 1200 
replies received from large consumers of coal. Porter and Ovitz* con¬ 
cluded that there is no reason to place special confidence in smokeless 
coals for safety in storage. In the large stock piles at Panama, Ap- 
palachin coals, with seventeen to twenty-one per cent of volatile 

* “Deterioration and Spontaneous Heating of Coal in Storage.” U. S. Bureau of 
Mines, Technical Paper 16, pp. 9—10, 1912. 



116 


ILLINOIS ENGINEERING EXPERIMENT STATION 


matter, give a great deal of trouble from spontaneous fires. Several 
large works report, moreover, that their low-volatile coals are more 
troublesome with respect to spontaneous fires than their high-volatile 
gas coals. 

The high-volatile coals of the West, are, to be sure, usually very 
liable to spontaneous heating, but owe this property to the chemical 
nature of their constituent substances rather than to the amount of 
volatile matter that they contain. Strange as it may seem, the oxy¬ 
gen content of coal appears to bear a direct relation to the avidity 
with which coal absorbs oxygen; high oxygen coals absorb oxygen 
readily, and, therefore, have a marked tendency to spontaneous com¬ 
bustion. 

Formerly the gradual heating of the coal and its final spontane¬ 
ous combustion was thought to be entirely or largely due to the pres¬ 
ence of sulphur. The chemical studies of Parr, Ovitz, Porter, and 
others have shown that a coal may heat as a result of the oxidation 
of the carbon, even when pyritic sulphur is absent. If pyritic sulphur 
is present, however, oxidation of this sulphur takes place, thereby 
supplying a definite additional source of heat and assisting in the 
oxidation of the carbon. The oxidation of the sulphur also acts me¬ 
chanically to break up the coal; thus by increasing the amount of 
small coal, the tendency to fire is increased. 

. Although sulphur has been shown to be only one of the factors 
producing heat, it is still thought by many who store coal to be the 
determining element in the heating of coal. 

J. G. Crawford* noted piles of coal containing from four to five 
per cent of sulphur which had been stored on the ground from four 
to six years without firing. 

Stansfieldf says: 

‘^Pyrites, by weathering, could hardly heat itself up to ignition point, much 
less the coal surrounding it; in fact, heaps of pyrite free from carbonaceous 
material are never known to fire spontaneously. 

^^In considering these arguments we must remember that there are different 
varieties of pyrites, that known as marcasite weathering much more rapidly than 
the ordinary variety. The fine fiakes of pyrites, sometimes scattered throughout 
the coal, are probably marcasite and certainly weather faster than the larger lumps. 

* Proceedings, International Railway Fuel Association, Vol, VII, p. 295, 1915. 

t “ Spontaneous Combustion of Coals,” An Investigation of the Coals of Canada, Vol. 
VI, pp. 110-111, 1912. 




THE STORAGE OF BITUMINOUS COAL 


117 


‘‘A single match may ignite a pile of shavings, a single flake of marcasite 
might cause a warm spot that might result in a coal pile firing. This might ex¬ 
plain the fact that the tendency for a coal pile to fire is not proportional to the 
percentage of sulphur or pyrites present. 

^‘We are not at present looking for something to heat the coal to its ignition 
point, but only to give it a little initial heating. If sulphur is liberated from 
pyrites and oxidizes (both actions being accompanied by an evolution of heat) at 
low temperatures, it might easily act as a starter, although the sulphur did not re¬ 
main as such to lower the ignition point. 

‘ ‘ The crucial question seems to be, does the coal or the pyrites generate heat 
the faster by its normal oxidation at low temperatures? The evidence seems to be 
strongly in favor of the answer: the coal. This would thus rule pyrites out of ac¬ 
count as the usual causes of fires. It is, of course, always conceivable that under 
certain circumstances this might be reversed and the pyrites blamed; but this 
probably seldom or never occurs. 

‘^On one point all parties are agreed. When flakes of pyrites weather they 
expand and fracture the coal, and thus expose more and fresh surfaces for oxida¬ 
tion and indirectly increase the danger of heating.” 

Near Danville, Illinois, the Missionfield Mining Company has a 
plant for separating pyrite from the coal and preparing the pyrite 
for market. According to the superintendent of the plant, even the 
fine pyrite passing through a 7/16-inch screen has never fired in the 
bin, except when there has been found in the pile a piece of wood 
or other carbonaceous substance which has acted as a match to start 
the combustion. 

In spite of the results of tests the opinion prevails very generally 
that a high sulphur coal is more likely to fire than one containing a 
small amount of pyrite, and an investigation should be undertaken to 
show the exact infiuence in storage piles of the sulphur content. It 
has been suggested that the pyrite may oxidize and set the sulphur 
free according to the reaction. 

FeS^+200=FeSo,+S 

and that the free sulphur having a low ignition point may act as an 
igniter as it does in a match or in gunpowder. It is certainly true 
that on many weathered coal dumps there is a deposit of yellowish 
white material which very closely resembles free sulphur. 

The effect of moisture upon the heating of coal is a much dis¬ 
puted question, although those who store coal are practically unani¬ 
mous in the opinion that water stimulates spontaneous combustion. 
On the other hand scientific investigations seem to indicate that coal 


118 


ILLINOIS ENGINEERING EXPERIMENT STATION 


oxidizes less when wet than when dry.* The effect of water in dis¬ 
integrating coal high in sulphur is undoubted. Vivian Lewes, of 
England, draws a sharp destination between wet coal and damp coal, 
the latter being considered dangerous. The undoubted fact that the 
top of a coal pile is warm after a rain is explained by the New South 
Wales Commission as due not to the fact that the water causes the 
coal to heat, but the pile being already hot inside heats the water which 
runs down into the pile and then returns as steam to the surface and 
heats it. 

Stansfieldf says: “It is probable that when our knowledge of the 
air circulation and rate of oxidation in coal piles is increased, water 
will be a good servant; at present it is a dangerous ally.'” 

Coal immersed in water does not deteriorate to any extent chem¬ 
ically nor does it disintegrate except as a result of handling. The 
amount of water absorbed does not affect the burning qualities of the 
coal. 

Instances in which water seemed to assist in stimulating sponta¬ 
neous combustion are quoted in connection with reports regarding coal 
stored by railroads. A pile is reported to have fired under conditions 
in which seepage from the water tank kept part of the pile damp. 
Another instance occurred in a low corner of a coal pile where water 
colleeted, but this corner was shut in by a side hill which excluded 
the air so that it is a question which agency caused the firing, the 
presence of the water or an insufficient amount of air. 

Most of the answers to the questionnaire agree in advising 
against storing on the ground on account of the presence of moisture, 
but an equally strong reason lies in the desirability of having a clean 
surface from which the coal may be taken up. 

39. Coking and Gas Making Properties .—There are few re¬ 
corded data concerning the effect of storage upon the coking prop¬ 
erties of coal, although the replies to the questionnaire agree generally 
in the opinion that heating injures the coal for this purpose. H. D. 
Hall, Superintendent of the By-product Plant of the Inland Steel 
Company, says that the gas rqade from stored coal does not differ ma¬ 
terially from that made from fresh coal. H. C. Porter, of the H. 
Koppers Company, says that the weathering of coal in the open has 

* A most comprehensive discussion of this subject by Ed^ar Stansfield. of McGill Uni¬ 
versity, will be found in An Investigation of the Coals of Canada, Vol. VI, pp. 95-120, 
1912 • 

t Ibid., p. 115. 



THE STORAGE OF BITUMINOUS COAL 


119 


a considerable effect upon the coking qualities. A. Ives, Superin¬ 
tendent of the American Zinc Company of Illinois, says that coal 
which is kept on the ground for more than thirty days deteriorates 
to an extent which renders it almost useless for gas making. 

Tests to determine the effects of the age of coal on coking quali¬ 
ties, made by J. B. Porter in Canada on coals varying in age from 
one week to twenty-one months, showed that while in the majority 
of cases the difference in the coke was very slight, in some cases there 
was a marked deterioration of the coking quality of the stored coal. 

J. B. Porter* says: “The coking quality of coal, even when 
stored carefully in sacks, does deteriorate somewhat with age, al¬ 
though not as much as is sometimes supposed, a fact which was con¬ 
firmed by later tests on comparable coals. It was, however, shown 
that different coals varied very much in their susceptibility to aging. ’ ’ 

“White has found,” according to Porter,! “that weathering 
materially lowers the hydrogen-oxygen ratio, and as suitability for 
coking decreases rapidly as this ratio falls below fifty-nine per cent, 
it is easy to see that a relatively small amount of weathering may 
produce a profound effect on the coking qualities of a coal in which 
this ratio is close to this limit.” 

A. R. DeHoll, Superintendent of the By-product Coke Depart¬ 
ment of the Inland Steel Company, says: 

‘‘We know by experience that if the coal is heated to such an extent that 
smoke appears, the coke resulting from this coal is merely a conglomerate of small 
pieces. The coal seems to have lost its cementing qualities and at the same time 
the heating value of the gas will decrease from forty to fifty B. t. u. In the 
cases wherein we were troubled with coal thus affected I have found that the 
yield of ammonia was only slightly affected, but the yield of tar more so. 

‘ ‘ In order to eliminate this trouble, I always use up the oldest coal, and when 
the shipping season stops at the first of December we reclaim the coal for our 
ovens on day turn in such a manner as to leave in our storage place room for coal 
taken from the opposite end of the pile. Thus by turning and airing the coal we 
have effectively eliminated coal fires in our operation. ’ ’ 

Experiments made under a cooperative agreement between the 
U. S. Bureau of Minesf and the Gas Experiment Station of the Uni¬ 
versity of Michigan upon West Virginia and Pennsylvania gas coals 
showed that coals, after being kept in storage for periods up to five 


* An Investigation of the Coals of Canada, Vol. VI, p. 27, 1912. 
t An Investigation of the Coals of Canada, Extra Vol., p. 172, 1915. 
t White, A. H., and Baker, Perry, “Coals Available for the Manufacture of Illumi¬ 
nating Gas.” U. S. Bureau of Mines, Bui. 6, 1911. 



120 


ILLINOIS ENGINEERING EXPERIMENT STATION 


years, showed changes in their gas making properties too small to be 
detected by the present methods of testing and analysis. Prof. A. H. 
White, of the University of Michigan, says: 

‘ ‘ Tlie coal was piled seven to nine feet deep in bins with separate compartments 
so that the coal was not moved until the time came for its particular compartment to 
be tested. The temperature of the coal in the pile was measured during the first 
few months and no spontaneous heating was detected. This is important because 
it is known that coal which has heated is inferior as a gas coal. The coal was 
exposed freely to all the effects of the climate of Southern Michigan, which is 
rather damp and with rather severe winters. 

‘‘The main body of the coals suffered little physical change during the five 
years but the top six inches crumbled considerably. Chemical analyses of the coal 
failed to reveal any material change, even in this top six inches, after weathering 
five years. Neither was there any material change in the absolute weight of the 
coal. Samples of the coal immersed in running water showed rather more change in 
chemical composition than did the coals exposed to the weather. 

“Gas coals of this type can be exposed to the weather in a rather severe 
climate for five years (provided they do not heat in storage) and at the end of 
the five years still be entirely satisfactory gas coals.’’ 

There is little evidence to support the opinion that the value of 
middle west coals for gas making decreases as a result of storage, since 
these coals have not been used for gas making until recently. 

40. Degradation or Breakage .—In connection with the storage 
of coal, degradation, i. e., the breakage of large lumps into smaller 
sizes, is the result of: 

(1) A physical change due to weathering which causes 

the lumps to crack and break. 

(2) Breakage due to handling. 

Coals in storage alternately dry out and absorb moisture. This 
process tends to break up the lumps; also, flakes of pyrites oxidize 
and assist in the breaking up process. Coals of high moisture content 
in general deteriorate from breakage due to weathering. 

Professor Parr* presents results with reference to the degrada¬ 
tion of coal stored one and one-half and six years. These results are 
given in Table 6. 


* “Effects of Storage upon the Properties of Coal.” Univ. of Ill. Eng. Exp. Sta., Bui. 
97, p. 35, 1917. 



THE STORAGE OF BITUMINOUS COAL 


121 


Table 6 

Increase in Fine Material After One and One-Half and Six Years of 

Storage 

(Basis of Eeference, the Total Coarse Material in the Original Coal 

Passing Over 14 inch Screen) 





Initial 

Storage 

After 1}^ Years 

After 6 Years 

Table 

No. 

Coal and County 

How 

Stored 

Dust 

Passing 

M-inch 

Screen 

Dust 

Passing 

M-inch 

Screen 

Increase 

in 

Per cent 
of 

Original 
Coal over 
H-inch 

Dust 

Passing 

H-inch 

Screen 

Increase 

in 

Per cent 
of 

Original 
Coal over 
H-inch 

I 

Nut: 

Sangamon. 

Open 

1.2 

13.2 

12.1 

31.9 

31.0 

2 

Nut: 

Vermilion. 

Open 

13.6 

24.0 

12.0 

35.0 

24.7 

3 

Nut: 

Williamson. 

Covered 

1.4 

11.0 

11.1 

13.9 

12.6 

4 

Screenings: 

Sangamon. 

Covered 

26.3 

38.5 

16.5 

45.1 

25.5 

5 

Screenings: 

Vermilion. 

Open 

37.7 

48.4 

17.1 

49.6 

19.1 

6 

Screenings: 

Williamson. 

Covered 

38.8 

45.4 

10.7 

50.6 

19.2 


Parr concludes from the results of these tests that the rate of 
disintegration is consistent for a given variety of coal and suggests 
that the oxidation of the organic material may be as largely respon¬ 
sible for this breaking down of the particles as the oxidation of the 
finely divided pyritic sulphur. The sulphur may or may not be dis¬ 
tributed through the texture of the coal; this characteristic has not 
been determined for Illinois coal. 

The amount of degradation depends upon the variety of coal, 
the method of handling, and to some extent upon the time the coal 
is in storage. The effect of time depends somewhat upon the size 
of the storage pile, since the depth to which the deterioration extends 
into any pile is not very great. 

Breakage of coal in handling is a matter of great importance 
where close sizing is practiced for domestic use, not only because it 
increases the amount of fines and thus the liability to firing, but also 
because it means rescreening and additional cost. There is very little 
reliable information on this subject at present. 
























122 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Ill experiments*' to determine the extent of breakage of Illinois 
coal falling through different heights and upon different materials, 
such as steel, concrete, and wood, L. A. Mylius found that wetting 
the coal thoroughly before dropping seems to decrease breakage ma¬ 
terially. Each coal has in itself a tendency to break which does not 
vary so long as the moisture content is the same. As a given coal 
gradually dries out its friability increases; thus a coal dried in stor¬ 
age with a decrease of from fifteen to eight per cent in moisture will 
break more readily on rehandling, owing to the change in moisture 
content alone. A coal which is wet before being handled seems to suffer 
less breakage from handling than one which has not been wet, but 
these statements should be more thoroughly tested before being 
presented as conclusive. In one of the discussions on coal storage at 
the International Railway Fuel Association it was stated that there 
was less breakage when the coal was handled wet. 

The apparatus used for Mylius’ tests, as shown in Fig. 56, con¬ 
sists of a steel framework inside of which a box is raised and lowered 
by means of ropes passing over pulleys at the top and attached to 
a small hand operated roller. The hinged bottom of the box can 
be dropped very quickly by means of strong springs. 

Tests on the degradation of coal, made by Porter and Ovitzf are 
described as follows: 

‘‘Fig. 57 shows the results of some comparative breakage tests made on lump 
coals to bring out this point. A 50-pound sample of screened lump (over 2 inches) 
was dropped four times from a height of six feet and the coal then sized by screen¬ 
ing into three portions, % inch, % inch—% inch and % inch—2 inches. The 
great friability of the low-volatile Applachian coals is clearly shown and the wide 
variation between different coal types. It is found in practice that dust and fine 
coal, when mixed with some larger coal, add greatly to the danger of spontaneous 
heating. A single instance from commercial practice will serve to illustrate this. 
The Calumet and Hecla Mining Company has three large coal storage piles of 125,- 
000 to 200,000 tons each, in which they store lump coal passed over 1%-inch bar 
screen just before placing on the piles. No spontaneous fires have occurred since 
they began this practice, although several fires had been experienced in the same 
kind of coal before that time.’’ 

The following values given by R. V. NorrisJ for anthracite coal 

* These experiments have been carried on in the laboratory of the Department of 
Mining Engineering at the University of Illinois, but they have been interrupted by the 
withdravsral of Mr. Mylius to join the Canadian Army, and no conclusive results are avail¬ 
able for publication at this time. 

t “The Spontaneous Combustion of Coal.” Original Communications, Eighth In¬ 
ternational Congress of Applied Chemistry, Vol. X, pp. 264-266, 1912. 

j: “The Storage of Anthracite Coal.” Trans., Am. Inst, of M. E., Vol. 38, p. 314 



THE STORAGE OF BITUMINOUS COAL 


123 


COAL 

/Va nams 

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BLOCATOP, ALA. 

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Fig. 57. Chart Showing Extent of Breakage in a 50-pound Sample of 
Screened Lump Coal (over 2 inches) dropped from a Height of Six 
Feet in Per Cent of Original Sample 

(From “The Spontaneous Combustion of Coal’’ by Porter and Ovitz) 


show the commercial importance of degradation from handling, be¬ 
cause with practically all bituminous coals the amount of degradation 
would be much greater than for anthracite although the depreciation 
in value for bituminous would not be so marked, except when bi¬ 
tuminous coals are intended for domestic purposes. 


“Loss IN Undersize in Passing Through Storage Bins 


Size of Coal 

Breakage into 
Smaller 
Prepared Sizes 

Per cent 

Breakage into 
Small Sizes 

Per cent 

Total Breakage 

Per cent 

Broken. 

19.57 

6.60 

26.17 

Eee. 

10.18 

8.50 

18.68 

Stove. 

4.92 

8.14 

13.06 

Nut. 

7.65 

7.65 

Pea. 


10.83 

10.83 

Buckwheat. 


4.06 

4.06 





























































































































































































124 


ILLINOIS ENGINEERING EXPERIMENT STATION 


‘‘Even taking half these figures, which would be most conservative, and as¬ 
suming perfect rescreening, the loss at seaboard on 1,000,000 tons of prepared and 
pea-coal in about the usual proportions would amount to $545,000, as shown in 
the following table: 


Size 

Original 

Final 

Quantity 

Price 

per 

Ton 

Total Value 

Quantity 

Price 

Per 

Ton 

Total Value 

Broken. 

Tons 

130,000 

225,000 

195,000 

200,000 

250,000 

$4.75 

5.00 

5.00 

5.00 

3.25 

2.50 

1.75 

$ 617,000 
1,125,000 
975,000 
1,000,000 
812,500 

Tons 

96,040 

191,770 

192,410 

215,040 

248,630 

35,515 

20,595 

$4.75 

5.00 

5.00 

5.00 

3.25 

2.50 

1.75 

$ 456,190.00 
958,850.00 
962,050.00 
1,075,200.00 
808,047.50 
88,787.50 

36,041.25 

Egg. 

Stove. 

Nut. 

Pea. 

Buckwheat. 

Rice 1 



Barley ). 



Total. 

1,000,000 


$4,529,500 

1,000,000 


$4,385,166.25 





‘ ‘ The loss in breakage, from this calculation, is 54.5 cents per ton, in addition 
to the cost of storage. 

‘ ‘ Many attempts have been made to reduce the breakage involved in handling 
through pockets, and this is often minimized by the use of shallow pockets, with 
resultant loss of storage; counter-chutes, spirals, and shelf-chutes in the deeper 
pockets, and the use of feeding-shafts, which, when properly maintained and in¬ 
telligently used, keeping them full, feeding in at the top as the coal is discharged 
from the bottom, certainly greatly reduce the losses by dropping. 

Breakage may be diminished by sliding coal along chutes or along 
the side of the pile rather than by dropping it. Coal moving in a 
large mass breaks less than single lumps. Drawing coal from the 
bottom of a pile under pressure results in heavy breakage. Handling 
prepared coal by scraping conveyors produces a breakage loss of from 
two to four per cent, according to the method of feeding and dis¬ 
charging, there being very little breakage during transit. Bucket 
elevators cause breakage of from two to five per cent according to 
the method of feeding and the discharging. 

The commercial importance of the breakage problem in connec¬ 
tion with the handling of coal is discussed very fully by Prof. E. A. 
Holbrook.* 


* “Dry Preparation of Bituminous Coal at Illinois Mines." Univ. of Ill. Eng. Exp. 
Sta., Bui. 88, 1916. 



































Fig. 


56. Apparatus Used to Determine the Extent of Breakage in Coal 
Caused by Dropping in Tests at the University of Illinois 






























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K* 9 t^ f' * ■• . V* »■'* ’ 


-v* .ia- V 


'7'^ :s.-^'-... smmSaK •■ ■ ■o, -.v.- ■/•. ^ ^ 




THE STORAGE OF BITUMINOUS COAL 


127 


41. Loss in Weight .—The loss in weight due to exposure to the 
air is a matter which seems to be generally misunderstood. Such 
loss undoubtedly occurs whenever the water evaporates from the 
coal. Since water, however, is not a heat producing element, but 
rather is a heat absorbing one, the loss in weight is an advantage, 
because pound for pound the coal has a higher heating value after 
the water has been evaporated than before. It has been shown by 
M. L. Nebel* that coal as it occurs in the ground is probably satu¬ 
rated with moisture and, although the moisture gradually dries out, 
it may be returned to the coal by immersing it in water. This fact of 
course has no practical application in the utilization of the coal, ex¬ 
cept in connection with the determination of its specific gravity. 


VII. Expense of Storing Coal 

Statements and estimates of the expense of storing and reclaim¬ 
ing coal have been submitted by many public service corporations, 
industries, coal dealers, and railroads. These estimates vary widely 
according to the conditions under which the storing is done and, for 
this reason, are not directly comparable. The reports were sub¬ 
mitted in response to the questionnaire, the form of which is shown on 
page 130, but in only a few cases did the replies contain detailed facts 
such as, for instance, the expense due to depreciation, interest, rental, 
insurance and overhead. Many stated that it was impossible to 
report these items separately. The estimates are summarized in the 
following list in which are also given page references indicating the 
number of the page in this circular on which more detailed information 
regarding the conditions of storage may be found. A study of these 
conditions is essential to a correct interpretation of items of expense 
reported. 

Other statements of the expense of storage may be found in the 
Proceedings of the International Railway Fuel Association.! 


*“ Specific Gravity Studies of Illinois Coals.” Univ. of Ill. Eng. Exp. Sta., Bui. 
89, p. 6, 1916. 

t Vol. VI, 123, Vol. VII, 263-264, 265-266, 267-268. 



128 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Expense of Storing and Reclaiming Coal 


Firm Storing Reclaiming Total 


Hand Storage 

Bohmer Coal Company, St. Louis, stored on 
ground and reclaimed by hand shoveling 

St. Bernard Mining Company, Nashville, Tenn., 
dumped from wagons, reclaimed directly 
into wagons, p. 16^3. 

Polar Wave Ice and Fuel Company, St. Louis, 

$.22 


$.15-.30 

hand labor, p. 161. 

Crystal Ice and Fuel Company, Danville, III., 
stored in bins by dumping, reclaimed by 
shoveling, p. 159. 

Ebner Ice and Cold Storage Company, Vin¬ 
cennes, Ind., by hand labor and conveyors, 
p. 161, for depreciation and interest, .154 
cents, also under water .214 cents 

Rock Island Fuel Company, Rock Island, III., 

.48 

$.16 

.64 

.17 

.368 

labor only, p. 159. 

University of Illinois Storage with motor truck 
and by hand, reclaimed by wagon loader. 

.08 

.10 

.18 

p. 42 and 47. 

Side Hill Storage, estimated in 1907, p. 56 

Locomotive Crane Storage 

For cost of locomotive cranes, see page 60. 

Estimated expense of operating locomotive 
crane, $1.50 per hour, or 3 cents per ton. 

.21-34 

.20 

.41-.54 

.19 

A large wholesale and retail coal company 
Commonwealth Edison Company, Chicago, labor 

.015 

.02 

.095* 

and materials only, p. 61. 

Clinchfield Fuel Company, Dante, Va., Crane 

.05 

.05 

.10 

and trestle, p. 64 and 67. 

A large wholesale and retail company . 

Pittsburgh Plate Glass Company, Crystal City, 

.0671 

.0655 

.1326 

.04-.20 

Mo., p. 165. 

Rockford Electric Company, Rockjord, III., 

.25 

.25 

.50 

p. 165 . 

American Zinc Company, E. St. Louis, III., 

.10 

.10 

.20 

p. 171 . 

Crerar-Clinch and Company, Chicago, hand 
and locomotive crane, p. 161 .... 

.20 

.15 

.35 

.25 


♦This total includes SO 04 for interest and $0.02 tor depreciation. 

















THE STORAGE OF BITUMINOUS COAL 


129 


Firm 

Storing 

Reclaiming 

Total 

Locomotive Crane Storage — Cont’d 




Mineral Point Zinc Company, Depue, III., 
p. 171 . 

$.05-.06 

$.05-.06 

$.10-12 

Estimate by C. G. Hall .. 



.2628 

Missouri, Kansas and Texas Ry., including'cost 
of track, p. 183. 

.035 

.035 

.07 

Chicago, Lake Shore and South Bend Ry., p. 181 



.12 

Grand Trunk Pacific Ry., p. 184 .... 

.08 

.062 

.142 

Atlantic Coast Line, p. 183. 



o 

r 

o 

Central of Georgia Railroad, p. 180 .... 

.0258 

.0209 

.0467 

Steam Shovel Storage 

Union Light and Power Company of St. Louis, 
dumped by hand, reloaded by steam 
shovel, p. 167. 

.10 

.10 

.20 

Bridge Storage 




Wisconsin Gas and Electric Company, Racine, 
Wis., p. 166. 

.08 

.22 

.30 

Berwind Fuel Company, Duluth, Minn., p. 82. 



.60 

Link-Belt Company, estimate for bridge stor¬ 
age, p. 82. 

.056 

.0515 

.1075 

Calumet and Hecla Mining Company, Calumet, 
Mich., Hunt system, steam shovel, p. 174 

Summer. 

Winter. 

.15 

.15 

.07M 

.22 

.26% 

Large swivel bridge, p. 82. 


.06 


Under-water Storage 




New Kentucky Coal Company, Kankakee, III., 
Storage of 250,000 tons, $20,000-130,000, 
pp. 100 and 101. 




Metropolitan Water District, Omaha, Nehr., 

p. 102 . 

.063 

.063 

.126 

Estimate by C. G. Hall, p. 106 .... 



.1823 

Peabody Coal Company, Lemont, III., pp. 104 

and 105. 

Estimated expense of operation . 
Estimated cost of equipment, $13,830 



.162 

Illinois Traction System, see pp. 88 and 89, for 
cost of plant. 




Western Electric Company, Chicago, p. 88 . 

.05 

.04 

.09 

National Zinc Company,Springfield, p. 90 1913 



.225 

u a u .. ^ 

.10 

.10 

.20 



















130 


ILLINOIS ENGINEERING EXPERIMENT STATION 


APPENDIX I 

QUESTIONNAIRE ON COAL SHORTAGE DATA 

1. Kind of Coal Stored State and District Sizes Stored Amount Kept 

Where Coal was Mined in Storage 


Semibituminous 

(Pocahontas, Central Pa., W. Md.) . 

Bituminous . 

Note: Please give definitely the district in each state from which the coal 
comes. 

2. How long is coal kept in storage? . 

3. Are sizes kept separate in storage? . 

4. Is slack removed before storage? . 

5. How long time elapses between the mining and storing? . 

6. What do you consider the best months to store? . 

7. Why do you consider this the best time to store? . 

8. Why do you store coal? .!. 

9. What do you consider the financial advantages of storing? . 


10. For what purpose is the stored coal to be used? . 

11. Is there any difference in the selling price of fresh and stored coal? . 

12. Does the coal decrease in heating value as a result of storage? . 

. If so, to what extent? . 

13. What loss is there through breakage as a result of storing and reclaiming the 

coal ? . 

14. Does the coal heat up after being stored? . 

If so, how soon? . 

15. What measures are taken to prevent heating? . 

16. In case of heating, how is coal handled? . 

17. To what extent is coal injured by such heating? . 




























THE STORAGE OF BITUMINOUS COAL 


131 


18. What method of storing is used? . 

19. What method is used for reclaiming the stored coal? . 

20. Is coal stored on the ground? . 

21. If not on what is the pile built up? . 

22. Is pile continuous or divided by partition wall? . 

23. Is storage under cover? . 

24. What is the shape of the storage piles? . 

25. What is the height of the storage piles? . 

26. What machines are used for storing? . 

27. What machines are used for reclaiming? . 

28. Are these machines satisfactory? .. 

29. If stored under water what percentage of water is retained by coal when 

taken from storage? . 

30. In storing are lumps allowed to roll down and accumulate at bottom of pile? 


31. What percentage of fines below ^ inches are present when stocked? . 

32. Cost of Storing Eeclaiming 

Overhead . 

Labor . 

Supplies . 

Depreciation on mechani¬ 
cal equipment . 

Interest on investment . 

Rental on land on which 

coal is stored . 

Insurance on equipment . 

Insurance on coal . 

Totals— . 

Note: If itemized costs are not available please give totals and state what 
totals include. 

33. Please give reference to any articles which have appeared descriptive of 
your storage. 

34. Information furnished by . 


Official position 
Company . 





































132 


ILLINOIS ENGINEERING EXPERIMENT STATION 


APPENDIX II 

SUMMARY OF CONCLUSIONS AND SUGGESTIONS 
REGARDING COAL STORAGE 

The questionnaire, presented on page 130, was sent out to a large number 
of firms and individuals and on the basis of replies a summary of conclusions and 
suggestions was prepared. This summary included as nearly as possible all the 
suggestions regarding coal storage contained in the replies. It was then sent to 
those who had replied to the questionnaire for an expression of opinion and the 
request was made that reasons for disagreement be given. The ]^esponses were 
most gratifying, not only because there was a general agreement wifti the conclu¬ 
sions, but because so much care was evidently taken in studying the summary. 
In many cases no answers were given to certain questions, possibly because the 
persons replying had had no experience with the particular phase of the subject 
in question and did not, therefore, wish to express an opinion. Certain answers of 
“NO’’ also do not indicate disagreement from the conclusions, but merely that 
the conclusion outlined does not represent the practice of the person answering 
the question or that the person has had no experience with that phase of the 
question. 

The answers have been tabulated under three heads: YES, NO, and DOUBT¬ 
FUL (?). The question mark does not necessarily imply that the conclusion is 
questioned, but may mean merely that the person replying had no data upon which 
to base an opinion. The tabulation of replies is presented, in the form in which 
the summary was submitted to firms and individuals, as follows: 


Conclusions and Suggestions Regarding Coal Storage 

(Submitted to 175 corporations or individuals storing coal) 

It is impossible to give definite rules and regulations regarding the storage 
of coal which will be universal in their application and each storage problem must 
be solved in accordance with such local conditions as the kind of coal to be stored, 
the space and appliances available, the capital obtainable, etc. The following 
are some suggestions which seem fairly to represent the results of present storage 
practice and of certain theoretical considerations based upon experimentation. 



THE STORAGE OF BITUMINOUS COAL 


133 


Coal is stored: 

1. To assure a regular supply when the mines are shut 
down or when coal is not delivered regularly by trans¬ 
portation companies. 



84 



2. To take advantage of low water freight rates 

3. Because the price is often less at certain seasons of 

the year, generally in the summer. 

4. To equalize the prices on the different sizes of coal 

5. To avoid the maintenance by the railroads of equip¬ 
ment which is used for only a part of the year 

6. Coal storage should not be considered only as a war 

expedient but as an essential part of all large coal 
using operations. 

7. Coal should be stored as near as possible at a point 

where it is to be used so as to avoid rehandling and to 
equalize transportation facilities. 

8. There is a considerable difference in the ease with which 

different coals oxidize and this must be considered in 
storing coal. 

9. Coal exposed to the air seems to lose some of the vola¬ 

tile ingredients which assist in producing spontaneous 
combustion; hence the greater the time elapsing between 
the mining and storing of the coal, the less is the liability 
to spontaneous combustion. 

10. The opinion formerly held that the chief source of 
spontaneous combustion is the pyrites (sulphur) in the 
coal has not been substantiated by experiments. There 
is, however, a wdde-spread opinion that coals high in 
sulphur are much more liable to spontaneous combustion 
than those low in sulphur and an effort is made by many 
in choosing a coal for storage to get one low in sulphur 

11. Although the oxidation of the sulphur is not the prin¬ 
cipal heat producing element, it tends to break up the 
lumps and thus increases the fine coal which fires easily 

12. Some coals and particularly those high in sulphur heat 

more readily if damp, and alternate wetting and drying 
is undoubtedly harmful. 


78 

87 

65 

74 

81 

79 

78 


64 


65 


71 


76 


6 

6 

11 


5 

1 


5 


5 


7 


2 


















134 


ILLINOIS ENGINEERING EXPERIMENT STATION 


13. 


14. 

15. 

16. 


17. 


18. 

19. 

20 . 


21 . 

22 . 

23. 

24. 



Yes 

No 

? 

All varieties of bituminous coal may be stored if of a 
proper size, if the fine coal and dust have been removed, 
and the coal is so handled that dust and small coal are 
not produced in the storing in excessive amounts . 

76 

4 

2 

Most varieties of bituminous coal are liable to sponta¬ 
neous combustion if the fine coal is not removed before 
storage . 

79 

1 

3 

In storing coal handle it so as to produce a minimum of 
dust and fine coal .. 

78 

1 


Owing to the cost of screening, to the difficulty of ar¬ 
ranging for it in large storage piles and to the difficulty 
of disposing of the screenings, it is often not practicable 
to store lump or screened coal . . . . . 

74 

5 

1 

Unless lump and screened coal are piled carefully and 
in low piles, crushing is likely to take place and produce 
dust near the bottom of the pile and thus to start spon¬ 
taneous combustion. 

69 

6 

3 

Pile as uniformly as possible and avoid stratification of 
large and small lumps. 

75 

4 


As liability to spontaneous combustion increases with 
the temperature, the cooler the coal is when stored, the 
less is the liability to spontaneous combustion . 

72 

5 

2 

Coal stored in cold weather is less likely to give trouble 
than that stored in summer and where summer storage 
is necessary the liability to heating is much less if the 
storage is carried on on cloudy or cool days 

70 

7 

3 

Coal of different varieties should not be mixed in storage 
if this can be helped, since such mixture seems to in¬ 
crease the liability to spontaneous combustion . 

72 

6 

4 

All storage appliances and arrangements should be so 
designed as to make it possible to load out the coal 
quickly. 

83 



Coal should not be stored in large piles unless provision 
is made for loading it out quickly in case of spontaneous 
combustion. 

72 

3 


Since moisture from below assists spontaneous combus¬ 
tion the storage pile should rest on a dry base . 

74 

2 

1 

















THE STORAGE OF BITUMINOUS COAL 


135 


25. 


26. 


27. 

28. 


29. 


30. 


31. 


32. 

33. 


34. 



Yes 

No 

? 

Since a small amount of water seems to aid spontaneous 
combustion, the drier the coal is when stored and during 
storage, the less is the liability to spontaneous com¬ 
bustion .. 

72 

1 

5 

Do not allow pieces of wood, greasy waste or other 
easily combustible material to be mixed with the coal 
during storage since they may form a starting point for 
a fire. 

78 

2 


Avoid contact between the coal and all such external 
sources of heat as steam pipes. 

82 



Pile coal as uniformly as possible and do not allow the 
lumps to roll to the^bottom or to one side of the pile and 
thus form a flue for the entrance of air to the interior of 
the pile. 

72 

2 

2 

Avoid air channels in a coal pile such as occur about 
imbedded pipes, the bents of trestles, cracks through 
bulkheads, etc., since fires frequently originate near 
such air channels. 

67 

3 

2 

Unless coal can be piled so that air can thoroughly cir¬ 
culate through the pile and thus carry off the heat as 
rapidly as it is generated (this is very difficult to accom¬ 
plish), the more closely fine coal is piled to exclude air the 
better . 

65 

3 

3 

Ventilation of coal piles by means of pipes running 
through the pile has usually not been successful in pre¬ 
venting spontaneous combustion, because the air does 
not circulate freely throughout the pile and in some 
cases the air currents through these pipes seem to be 
starting points for fires. 

63 

2 

3 

The great objection to ventilating systems is that they 
interfere with the handling of the coal. 

75 

1 


There is great difference of opinion in regard to the 
height of piles in which coal may be stored safely. Coal 
seems to fire almost as quickly in low piles as in high 
and as often near the top or outside of a high pile as 
near the bottom. The principal disadvantage of high 
piles is that coal in them cannot be so readily removed 
as from a low pile. 

65 

5 


Water is not generally successfully applied in extinguish¬ 
ing fire in a coal pile, because it is impossible thoroughly 
to saturate the pile. A small amount seems to aid 
spontaneous combustion. 

73 

2 





















136 


ILLINOIS ENGINEERING EXPERIMENT STATION 


35. 

36. 

37. 

38. 

39. 

40. 


41. 

42. 


43. 


44. 


45. 


46. 



No 

Yes 

? 

The deterioration in coal stored under water is negligible. 
Such coal absorbs little extra moisture. 

74. 

1 


With under-water storage if the entire coal pile is not 
covered, the part of the pile above the water line is 
liable to spontaneous combustion. 

64 


3 

The white coating on the outside of some coal piles is 
very thin and does not affect the value of the stored coal 

66 

5 

2 

The best method of handling coal in danger of firing is to 
load it out and scatter it so that it will be thoroughly 
cooled off. 

75 


1 

Coal which has a tendency to spontaneous combustion 
should be turned over frequently to keep down the tem¬ 
perature, although this causes an increase in breakage 

71 

3 

3 

If possible, stored coal should not be moved until it is to 
be used, unless it is heating, since piles which have ap¬ 
parently been safe have taken fire when opened to the 
air and the coal moved elsewhere, probably because of 
the opening up of new faces for oxidation .... 

75 

1 

1 

Coal which has once heated and cooled is not subject to 
the same oxidizing processes as fresh coal 

64 

3 

2 

Coal which has been in storage is considered by many 
to burn less freely when fired in a furnace, but this is 
largely prejudice and certainly can be overcome by 
keeping a thinner bed on the grate than with fresh coal 
and by regulating the draft. 

60 

8 

2 

The decrease in heating value as a result of storing coal 
is small unless the coal has heated up sufficiently to de¬ 
compose the coal or to drive off the volatile ingredients 
and the loss of moisture from the coal may increase the 
heating power per pound of coal. 

70 

1 

1 

The coking properties of eastern bituminous coals are 
not materially affected by storing unless the coal heats, 
but the coking properties of Illinois and other Middle 
West coals are seriously affected or destroyed by storage 

53 

1 

4 

The best preventive of loss in coal storage is the con¬ 
stant inspection and watching of the coal for incipient 
heating and immediate removal of coal from the spot 
affected. 

73 



Other suggestions. 



















THE STORAGE OF BITUMINOUS COAL 


137 


The following is a digest of the answers given to the summary of conclusions, 
listed on pages 133-136, which could not he included under the headings listed as 
“Yes,“No,’’ and These opinions show that the experiences of those 

storing coal are by no means the same and that local conditions evidently have a 
great deal to do with the opinions expressed. 

Reasons for Storing Coal 

1. To assure a regular supply when the mines are shut down or when coal 
is not delivered regularly by transportation companies. 

2. To take advantage of low water freight rates. 

3. Because the price is often less at certain seasons of the year, generally in 
the summer or spring. 

4. To equalize the prices on the different sizes of coal. 

5. To avoid the maintenance by the railroads of equipment that is used for 
only a part of the year. 

Comments: 

‘ ‘ To have a supply on hand for special seasons, such as during the grain 
rush. ’ ’ 

‘ ‘ To reduce cost of production at the mine by giving more uniform run¬ 
ning time and thus utilizing labor and equipment to best advantage. ’ ’ 

‘ ‘ To provide against labor unrest at the mines. ’ ’ 

‘ ‘ To equalize distribution of coal. ’ ’ 

“Make 3 to read, because the producers will often make price conces¬ 
sions on sized coal at certain seasons of the year (generally in the summer) 
which will offset the storage expense incurred by the consumer. ’ ’ 

“Amend 4 to read: From the standpoint of the producer it is advanta¬ 
geous to store some sizes at the mines or at distributing centers to equalize 
more nearly the prices on different sizes of coal.’’ 

“Most of the large dock companies contract their tonnage at a fixed 
price for the season.” 

‘ ‘ Screenings may be higher in summer than in spring and fall on ac¬ 
count of decreased operations of mines and lack of demand for screened 
sizes.’’ 

Advisability of Storage 

6. Coal storage should not be considered only as a war expedient but as an 
essential part of all large coal using operations. 

Comments: 

“May be true at some industrial plants, never true on a railroad. The 
storage of coal on a railroad is done only to meet a possible shortage of coal 
due to mine strikes or other causes. It is always more expensive for a 
railroad to store coal than it is to rely upon a current supply the year around 
.Seasonable use of equipment, or traffic conditions, would not in- 



138 


ILLINOIS ENGINEERING EXPERIMENT STATION 


fluence the storage of coal on a railroad as the expense of handling and stor¬ 
ing is great enough to overcome any or all these conditions.' ’ 

“Should be more zealously practiced in peace times than during war. 
Should be strictly limited in war times. ’ ’ 

Place of Storing 

7. Coal should be stored as near as possible to a point where it is to be 
used so as to avoid rehandling and to equalize transportation facilities. 

Comments: 

“Eehandling is a preventive against fires and is an advantage where 
coal is to be used for coke and is pulverized anyhow. “ 

‘ ‘ Should be stored at point of use and at mines. ’ ’ 

“Preferably so, but in order to avoid transportation difficulties, rather 
than for the reasons given. Coal can be unloaded into storage at some in¬ 
termediate point and later loaded up and forwarded to its destination on the 
original freight rate. ’ ’ 

‘ ‘ All modern mines should have storage at the mines as well as at point 
of consumption.^' 

“Eailroads should store heavily in spring months, February 1 to May 
1, so that they can serve the public and keep their locomotives and cars busy 
in the dull season." 

Liability to Spontaneous Combustion 

8. There is a considerable difference in the ease with which different coals 
oxidize and this must be considered in storing coal. 

Comments: 

‘ ‘ Broadly eastern and western coal should never be stored together.' ’ 
“Not of great practical importance among the high grade Appalachian 
coals; applies to essentially different types of coal." 

“You can store western coals without loss and danger from heating and 
it becomes a question of going as close as you can to the danger line to get 
the storage." 

9. Coal exposed to the air seems to lose some of the volatile ingredients 
which assist in producing spontaneous combustion; hence the greater the 
time elapsing between the mining and storing of the coal, the less is the 
liability to spontaneous combustion. 

Comments: 

‘ ‘ The general opinion is that it is not the loss of volatile ingredients 
which lessens the liability to spontaneous combustion of coal which has been 
exposed to air for a period of time before storing, but rather it is believed 
that during this preliminary period of exposure to air, the surfaces of the 
coal have become somewhat satisfied in their capacity for absorbing oxygen 
and the rate of absorption becomes less. Since the oxygen combines chem- 


THE STORAGE OF BITUMINOUS COAL 


139 


ically with generation of heat, the faster the rate of absorption, the greater 
will be the tendency to spontaneous combustion. ^ ’ 

Think that this is due to completed oxidation and degradation of all 
sulphur compounds. I have never heard that the extension of time between 
mining and storage minimized chances of combustion. It is very interesting. ^ ^ 

‘ ‘ Seems reasonable, but as car or boat must be unloaded on receipt, do 
not see much value in the suggestion. ’ ’ 

‘ ‘ Coal which has passed through the heating process successfully, that is, 
without ignition may lay for years without further heating. ’ ’ 

‘ ‘ Depends on whether the decreased liability of fire is more essential 
than the decreased coking qualities of the coal.’’ 

‘ ‘ Our experience has been that coal obtained from western Kentucky 
coal fields is much more likely to fire in storage than coal from eastern 
Kentucky coal fields.” 

“Cannot confirm conclusion, as coal that had been in storage for years 
took fire after it had been moved and restored.” 

“Do not notice any difference between storage at mines and distant 
points. ’ ’ 

“Probably but not confirmed by our practice.” 

‘ ‘ The loss of volatile matter, if any, is irrelevant and immaterial; it has 
nothing to do with the liability to spontaneous heating which is caused rather 
by surface oxidation.” 

“I doubt this difference being enough to give it commercial considera¬ 
tion. ’ ’ 

“The reason for this is probably that moisture is less.” 

“Is there not some ambiguity possible in this paragraph? Evidently 
refers to storage of coal in room at mines, not storage of coal in large quan¬ 
tities by mining companies at surface. Public might interpret this to mean 
feasibility of operators storing large quantities of coal at surface during 
periods of slack demand.” 

“Since coal has a limited absorbing power for oxygen, after the surfaces 
are exposed to the air for some time there is less liability to spontaneous 
combustion. ’ ’ 

Effect of Sulphur on Spontaneous Combustion 

The opinion formerly held that the chief source of spontaneous combus¬ 
tion is the pyrites (sulphur) in the coal has not been substantiated by ex¬ 
periments. There is, however, a wide-spread opinion that coals high in 
sulphur are much more liable to spontaneous combustion than those low 
in sulphur and an effort is made by many in choosing a coal for storage 
to get one low in sulphur. 

Comments: 

“There seems to be a rather general impression that sulphur is the 
determining factor of spontaneous combustion. In some analyses of samples 
which I took, the coal analyzed anywhere from four to five per cent sulphur, 
and this pile has been on the ground for over four years and another pile of 


140 


ILLINOIS ENGINEERING EXPERIMENT STATION 


the same coal for a period of six years without firing. This seems to be 
conclusive evidence that sulphur is not the determining factor. 

“Pocahontas, New Eiver and other high grade smokeless coals, which 
are low in sulphur, are extremely liable to fire, undoubtedly caused by oxida¬ 
tion, as we have frequently found small fires within two feet of the top of 
a forty-foot pile and again at the floor in the very center.” 

“I have wondered w^hether pyrite and iron nail and water might not 
start a fire. See Watt’s Dictionary of Chemistry on the Result of mixing 
pyrite and wet nails under a clay pot. An explosion takes place the steam 
blowing off the clay cap. ’ ’ 

“We have never had trouble in storing West Virginia coal which is low 
in sulphur. All the coal which we stored this year and which caught on fire 
was high in sulphur. ’ ’ 

‘ ‘ Pocahontas with lower sulphur gives more trouble than Pittsburgh 
with higher sulphur.” 

“All cases of spontaneous combustion observed have been high or mod¬ 
erately high sulphur coals.” 

‘ ‘ The sulphur is generally associated with elements that promote sponta¬ 
neous combustion.” 

‘ ‘ This is the general practice and opinion. I cannot vouch for its correct¬ 
ness. ’ ’ 

‘ ‘ This belief is losing strength. ’ ’ 

‘ ‘ The fact that coal is low in sulphur is, in my opinion, no evidence that 
it is a suitable coal for storage. The coal on the Milwaukee and Western 
Fuel Company docks at Milwaukee have been on fire for a number of years. 
The coal is unloaded in the summer, immediately begins to heat and they 
never succeed in extinguishing the fire until the next cargo comes in the 
following year. This coal is ^-inch Youghiogheny slack containing not to 
exceed .75 sulphur. On the other hand I have personally stored in Louisville, 
Kentucky, a large tonnage of a straight creek coal containing about the 
same amount of sulphur and have had no trouble whatever with the same 
heating although the coal was piled twenty feet high and remained in stor¬ 
age two years.” 

11. Although the oxidation of the sulphur is not the principal heat producing 
element, it tends to break up the lumps and thus increases the fine coal 
which fires easily. 

Comments: 

“Therefore the presence of the sulphur facilitates.” 

“Do not concur in the conclusion, as in warm weather the heating takes 
place before there is time for such disintegration.” 

“I have stored considerable lump coal which was high in sulphur and 
have taken the same out of storage four or five months later and have not 
found that the high sulphur coal caused any more degradation than any 
other class of coal. I have stored the majestic lump coal from the mine in 
Prairie County, which is extremely low in sulphur, and have found that it 
breaks up fully as much as high sulphured coal.” 


THE STORAGE OF BITUMINOUS COAL 


141 


Effect of Moisture on Spontaneous Combustion 

12. Some coals and particularly those high in sulphur heat more readily if 
damp, and alternate wetting and drying is undoubtedly harmful. 

Comments: 

‘ ‘ Make to read most instead of some coals. ’ ’ 

‘ ‘ Moisture is a cause of spontaneous combustion. ’ ’ 

‘‘Not true of the hard bituminuous coal, like McAlester, Oklahoma, Colo¬ 
rado and Pennsylvania bituminous.^’ 

‘ ‘ All the coal that I have ever stored has been stored in the open so that 
same has been exposed to the weather and the alternate wetting and drying 
but have never noticed that this had anything to do with the coal firing, 
although some of the coal stored was high in sulphur and did not fire.” 


Belation of Size of Coal to Spontaneous Combustion 

13. All varieties of bituminous coal may be stored if of a proper size, if the 
fine coal and dust have been removed, and the coal is so handled that dust 
and small coal are not produced in the storing in excessive amounts. 

Comments: 

“Do not think many coals can be handled in this way successfully.” 
“Yes, but impracticable.” 

‘ ‘ All is a sweeping word. Should prefer nearly all or probably all. ’ ’ 
“We have never had any trouble with lump coal, but have had trouble 
with mine run.” 

“And the pile is not too high.” 

“Excepting unwashed screenings.” ' 

“Impracticable and almost impossible.” 

‘ ‘ Desirable; not always practicable. ’ ’ 

‘ ‘ Cleaned coal undoubtedly has less liability to fire than coal with slack. ’ ’ 
‘ ‘ Fine coal should be removed thoroughly or else run of mine stored. 
Partial ventilation worse.than none.” 

“Some bituminous coal will slack and then is no longer sized and is 
likely to burn.” 

“Hard to do and expensive.” 

“Simply a matter of ventilation.” 

“So far I have had no experience in storing coal with the fine dust re¬ 
moved. In ordinary commercial undertakings where large volumes of coal 
■are to be stored, it seldom happens that the fine dust is removed. I, there¬ 
fore, do not know what effect it would have if such could be accomplished. ’ ’ 
“All kinds may be kept if stored properly. We store dust and slack 
under water.” 

“Not practicable for railroads.” 

“Can store low sulphur mine run coal with slack in it if properly 
handled. ’ ’ 


142 


ILLINOIS ENGINEERING EXPERIMENT STATION 


‘‘I believe that the character of coal has a great deal to do with spon¬ 
taneous combustion, in that a soft, porous coal which fires much more quickly 
than a more solid one, possibly due to additional breakage and water, and 
moisture absorption by the porous coal.” 

”As a result of our experience this year we have decided to store only 
lump coal in the future, getting coal that is as free from sulphur as possible. 
We will store it in a number of small piles of not over 1500 to 2000 tons 
each separating the piles by a distance sufficient to prevent the spread of 
fire. ’ ^ 

” Heating in storage coal is proportional to the amount of coal surface 
(not pile surface) in contact with air. If the sizes of the lumps are large, 
the amount of surface exposed is relatively small, and so too is the amount 
of heat evolved. If, however, the pieces of coal are small, including a con¬ 
siderable amount of coal dust, the amount of contact surface is enormously 
increased, the amount of heat evolved is also increased, and the danger of 
the temperature of the coal rising to a point where active combustion will 
take place is much greater. ’ ’ 

‘^This would indicate two principal ways of storing coal so that it will 
not take fire: 

(1) Store large lumps only, thus reducing the amount of surface exposed 
to the air. 

(2) Store fine coal only, packed so tightly that there will be no voids 
through which air can circulate.” 

“The friability or ease of breakage of coal is a very important factor 
affecting spontaneous combustion and is the cause of the prevalence of this 
trouble with semibituminous coals.” 

“Use screened coal for storage. Size of piles, kind of weather condi¬ 
tions, conditions of storage and sulphur content are then of minor impor¬ 
tance. ’ ’ 

“We cover our coal pile with fine raw dust when we discover the top or 
outside of the pile burning, thus preventing the air having access to coal and 
increasing the fire. We are able to successfully check a fire in this manner 
for a few weeks until we are ready to move the pile.” 

14. Most varieties of bituminous coal are liable to spontaneous combustion 
if the fine coal is not removed before storage. 

Comments: 

“Not high grade hard bituminous.” 

“It is best to store mine run coal in small piles to lessen danger of 
spontaneous combustion. ’ ’ 

^‘To a certain extent.” 

“More liable.” 

“We have never been successful in storing either screenings or mine run 
coal in large piles above ground. In our storage operations at the present 
time we are confining ourselves to selected mine run. In making this selection 
we choose coal having a very small percentage of screenings in it. We find 
that even this selected coal when piled in large piles will start heating and 
eventually fire.” 


THE STORAGE OF BITUMINOUS COAL 


143 


‘‘Choose the right coal to store. Store screened coal if in doubt.’’ 

‘ ‘ I think that the quality and structure of the coal placed ii. storage is of 
more importance than the manner in which the lump or screening coal is 
piled. If the coal is soft, it will undoubtedly break up and in these days when 
labor is so scarce, it is necessary to handle more of the coal with some mechan¬ 
ical device, particularly by a clam-shell. This manner of handling is very 
rough but w^e have a number of piles fourteen to sixteen feet high of lump, 
egg and nut which have been handled in this manner and we have had no 
trouble with spontaneous combustion.” 

In storing coal handle it so as to produce a minimum of dust and fine 
coal. 

Comments: 

“Not practicable for railroads.” 

“Yes, where possible; depends on machinery, quantity, quality of coal 
and ground area.” 

Owing to the cost of screening, to the difficulty of arranging for it in large 
storage piles and to the difficulty of disposing of the screenings, it is 
often not practicable to store lump or screened coal. 

Comments: 

“Lump coal that is practically free from fines or dust is to a large 
extent self ventilating and therefore safe for a reasonable time if other con¬ 
ditions are favorable. On the other hand, fine coal entirely free from lumps 
which would form air pockets and chimneys may be stocked almost as safely 
as the lump. A combination of the two, such as run of mine, is dangerous.” 

“We store as much crushed coal as possible.” 

“There is no difficulty in disposing of the screenings. When we buy 
coal for storage we have it screened at the mine, and the screenings are used 
for our daily service.” 

“It is perfectly practicable to store lump or screened coal but such coal 
costs more per ton.” 

‘ ‘ This was true until the last few years. During 1916-17 there was a very 
large demand for screenings. ’ ’ 

“Storage of screenings is dangerous under any conditions.” 

‘ ‘ Depends upon intended use of coal. ’ ’ 

“Depends on coal.” 

“Coal should be screened at the mine and only the sizes not readily 
marketable should be stored. This probably would mean in normal times 
that there is a supply of lump and egg coal in the summer which would be 
the grade that the ordinary householder should store. At the present time 
it is clearly developed that the distribution of domestic coal burdens the 
railroads to a greater extent for the amount of tonnage involved than any 
other class of coal business. The movement, switching and placing in single 
cars results in greater delay to equipment, greater loss of efficiency from 


144 


ILLINOIS ENGINEERING EXPERIMENT STATION 


motive power and engine crews and in every way increases the operating 
difficulties. ’ ’ 

“I would say sometimes instead of often. It is generally practicable 
and the expense of it is generally a reasonable insurance.’’ 

Height of File 

17. Unless lump and screened coal are piled carefully and in low piles, crush¬ 
ing is likely to take place and produce dust near the bottom of the pile 
and thus to start spontaneous combustion. 

Comments: 

‘‘We have piled lump coal in piles thirty feet high and have never had 
trouble with spontaneous combustion.” 

‘ ‘ Crushing has not been noticed in piles twenty-five feet high. Fires 
start at a depth between four and eight feet.” 

‘‘We do not find it so. Pile as high as sixty feet with little crushing.” 

‘‘Don’t store in piles over eight feet high.” 

‘ ‘ Depends on the character of the coal. ’ ’ 

“Where coal is placed in storage, it should not be scattered over a con¬ 
siderable area in thin layers, but should be piled in one mass as much as 
possible. ’ ’ 

“Weight is a big factor; so restrict open air storage to piles eight feet 
high. Under-water storage is the best.” 

Uniform Piling 

18. Pile as uniformly as possible and avoid stratification of large and small 
lumps. 

Comments: 

“I have replied ‘no’ as we store in the neighborhood of 1,000,000 tons 
coals per year and it is absolutely impossible to avoid stratification of the 
large and small lumps.” 

“Impracticable unless the coal is put into a pit or a bin. When piled 
in a pyramidal pile, fine coal will stay on the ridge and the larger sizes roll 
to the bottom and edge.” 

“Impracticable to follow out this suggestion.” 

“Not practicable for railroads.” 

“True for some coals, not for others.” 

“It is further important that the tops of all piles be finished off as 
nearly level as possible, avoiding to as large an extent as possible peaks and 
valleys over the surface. In the unloading of coal from buckets into storage 
the larger lumps tend to roll to the bottom of the pile along the surface of 
the coal already in storage, so that unless care is taken in the dumping a ~ 
coal pile will consist of fine coal in the center with a fringe of large and in¬ 
termediate lumps along its edges. Fires very frequently start along these 
edges, for obvious reasons, and if the coal is to be kept in storage any great 
length of time the lumps should be either removed or the whole covered with 


THE STORAGE OF BITUMINOUS COAL 


145 


fine coal so as to remove from contact with the air the mixture of lumps and 
fines. ’ ’ 

“Very important.’^ 

Temperature at Time of Storage 

19. As liability to spontaneous combustion increases -with the temperature, 
the cooler the coal is when stored, the less is the liability to spontaneous 
combustion. 

Comments: 

“We commence storing coal at the head of Lake Superior at the opening 
of navigation, but have never had fires during the summer time. They usually 
make their first appearance during the month of September and we have the 
situation well in hand prior to December 1.” 

‘ ‘ The variation in the temperature of mined coal is so slight that I 
question whether this would have any bearing. ’ ’ 

‘ ‘ Theoretically but would not make much difference in practice. ’ ’ 

‘ ‘ Believe this will effect but short delay. ’ ’ 

‘ ‘ Do not believe this applies to large and deep storage. Outside temper¬ 
ature of no account in such cases. “ 

“Yes, for the time being, but the pile will not be permanently safe until 
it has gone through a summer, ’ ^ 

“Doubt if there is anything in this suggestion, as the majority of our 
fires occur after the coal has been stored for some time and bear no relation 
to the temperature of the coal at the time it was placed in storage, as all our 
coal is stored in the open. “ 

“Possibly slight effect. 

“Yes; but negligible compared with item of fine, fresh coal dust.” 

“In cold countries storage in the open is less liable to spontaneous com¬ 
bustion than storage under cover.” 

20. Coal stored in cold weather is less likely to give trouble than that stored 
in summer and where summer storage is necessary the liability to heating 
is much less if the storage is carried on on cloudy or cool days. 

Comments : 

“Difference in temperature of the coal at the time of storing may have 
some influence, but under ordinary conditions where large quantities of coal 
are stored, there is very little choice as to the time the coal can be put down. ’ ’ 

‘ ‘ Naturally, we have to store our coal regardless of weather conditions. ’ ’ 
“Perhaps at the time but doubt importance.” 

“Not important.” 

“Believe this is of little benefit.” 

“Do not find any difference in summer and winter storage.” 

“Bather a fine distinction.” 

“Would omit this. Impracticable.” 

“Yes, but how can such days be chosen? ” 

“Yes; but negligible compared with item of fine, fresh coal dust.” 


146 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Effect of Mixing Coals in Storage 

21. Coal of different varieties should not be mixed in storage if this can be 
helped, since such mixture seems to increase the liability to spontaneous 
combustion. 

Comments: 

‘^Extremely important. We have experienced no trouble with the heating 
of stored coal, and the only time we have ever had a fire on our dock was when 
we bought a number of different kinds of coal. We have our coal dock situated 
close to the brewery and we generally purchase our coal before the opening of 
navigation, and have such a capacity that the coal can come in almost as fast as 
the companies desire to send it to us, all, of course, coming in during the season 
of navigation. Our usual method is to purchase our entire season’s supply from 
one company and secure all the coal from one mine. Mixed coals are not only 
objectionable on account of the danger of spontaneous combustion, but different 
coals require different methods of firing. ’ ’ 

^‘If coal that is known to give trouble from spontaneous combustion is mixed 
with coal that does not, it will undoubtedly increase the liability for the sponta¬ 
neous combustion of that given pile. However, if two coals are mixed together 
in which there is very little difficulty of spontaneous combustion, I doubt if it 
makes very much difference if they are mixed or not.” 

” Believe this effect is more a result of stratification than of difference of 
quality. ’ ’ 

'^Probably true and vital to docks storing large quantities of coal.” 

“We mix our coals.” 

“Not borne out by our experience.” 

“We have not found this to be true.” 

‘ ‘ Should never be mixed in pile. ’ ’ 

“Highly important.” 

‘ ‘ Do not believe this. ’ ’ 

“Coal stored from different mines together if not submerged appears in¬ 
advisable. ’ ’ 

“Depends on meaning of varieties; in general, yes.” 

“Know case where two coals, which in themselves will not fire, yet fired 
when stored together, but a few tons of coal which fires readily will set a pile on 
fire. May be likened to a hot cigar ash or match thrown into a waste basket. ’ ’ 
“Have not heard of any evidence of this; do not see any reason to believe 

it.” 

Precautions Which Prevent Fires 

22. All storage appliances and arrangements should be so designed as to make 
it possible to load out the coal quickly. 

23. Coal should not be stored in large piles unless provision is made for load¬ 
ing it out quickly in case of spontaneous combustion. 


THE STORAGE OF BITUMINOUS COAL 


147 


Comments: 

‘‘Yes; very important/' 

Would suggest that something be said in regard to breaks in piles where 
large quantities of coal are stored, so that if one section of the pile fires the entire 
tonnage would not have to be moved." 

‘ ‘ A pile of coal will give several weeks ’ warning of an impending fire.'' 

“We always leave sufficient room near our storage piles to enable us by 
means of a scraper run by a motor to turn over such parts of the pile as show to 
be heating. This is the only way we have been able to successfully fight heating 
in coal piles." 

24. Since moisture from below assists spontaneous combustion the storage pile 
should rest on a dry base. 

Comments: 

‘ ‘ Yes, in case of dry storage. ’' 

‘ ‘ Snow or rain on the pile and then covered is very dangerous, particularly 
snow. ’' 

‘ ‘ Have not observed this, but if true, moisture is driven off before ignition.'' 

‘ ‘ Eemove all refuse and provide drainage.'' 

“Fires do not originate at the base." 

“With some coal." 

‘ ‘ Do not find that moisture at base changes situation. ’ ’ 

“Our conditions are such that we cannot determine the effect of water on 
the bottom of the storage pile. We have found an equal number of fires twenty 
feet from the water and this would make it approximately thirty feet from the 
top of the pile. We do not believe that the fire originates on account of water at 
base of piles." 

‘ ‘ Questionable; some store part under water, part above.'' 

“Becomes saturated at base, evidently where fire always starts." 

25. Since a small amount of water seems to aid spontaneous combustion, the 
drier the coal is when stored and during storage, the less is the liability 
to spontaneous combustion. 

Comments: 

“ I do not have the experience permitting me to question this but it looks 
doubtful as the chemical actions of moistening cannot take place once the hydra¬ 
tion is completed. However, dehydration may later enable oxidation to act on 
the coal." 

“Generally yes." 

“Is this based on theory or experiment? " (An opinion expressed generally 
in the discussions of the International Kailway Fuel Association). 

‘ ‘ Doubtful.'' 

‘ ‘ Possibly.'' 

“When I was fleet engineer of the Pacific Station, about ten years ago, I 
used to have the colliers take on their loads with several lines of hose playing into 
the holds. I acted on the principle that, while a small quantity of moisture might 


148 


ILLINOIS ENGINEERING EXPERIMENT STATION 


do harm, a liberal wetting would be a good thing. The scheme appeared to 
work all right.’’ 

Experiments by the U. S. Bureau of Mines show a lack of uniformity in the 
action of coals toward oxygen in the presence of moisture. In one case the dry 
coal oxidizes faster and in another case the moist coal oxidizes faster; also con¬ 
flicting results have been obtained by different investigators. 

Cause of Fires Other Than Spontaneous Combustion 

26. Do not allow pieces of wood, greasy waste or other easily combustible mate¬ 
rial to be mixed with the coal during storage since they may form a starting 
point for a Are. 

Comments: 

‘‘Unable to control usually.” 

“I have never observed this. Pieces of wood have no apparent effect, and 
I doubt that waste saturated with mineral oil would make any difference. ’ ’ 

‘ ‘ Also avoid irregularities in structure of walls and floors such as angles and 
pockets. ’ ’ 

“Almost invariably have found this the cause of our flres in the coal piles. 
In other cases the fires have started near trestle post or stubbing piles.” 

“Greasy waste buried in coal will invariably fire.” 

“Very important. Consider this most important.” 

“From my observation this is the most frequent cause of fires if the facts 
were known. Should be made clear that when a fire is once started it cannot be 
classed as spontaneous combustion. Subject to be divided: (1) Prevention of 
cause of spontaneous combustion. (2) Handling of fire when once started.” 

27. Avoid contact between the coal and all such external sources of heat as 
steam pipes. 

Comments: 

“My several experiences with fires in bunkers on board naval vessels were in 
each case associated with a hot steam pipe or bulknead heated by proximity to 
steam boilers.” 

“Yes; either live or exhaust or over poorly installed exhaust lines which 
rust out and allow moisture and heat to reach pile.” 

“Most emphatically.” 

28. Pile coal as uniformly as possible and do not allow the lumps to roll to 
the bottom or to one side of the pile and thus form a flue for the entrance 
of air to the interior of the pile. 

Comments: 

“Impossible to prevent the lumps rolling to the bottom of the pile.” 

“The coarser the coal, the greater the voids through which air may enter.” 
“Seems desirable. Not practicable in our case.” 

‘ ‘ Hardly practicable. ’ ’ 

‘ ‘ Impracticable. ’ ’ 


THE STORAGE OF BITUMINOUS COAL 


149 


‘ ‘We aim to keep the bulkheads fairly high.” 

‘‘Cannot be avoided.’^ 

“Cannot be helped in high piles. 

“Inconsistent. Universal ventilation is a good thing. 

Rather impracticable for a railroad to do this. Let the air in, so that any 
heat generated will be carried ofif.’^ 

“Very important.^' 

“Difficult to comply with, as regardless of the manner in which the coal is 
unloaded lumps will roll to the bottom and sides of the pile. If lump or egg coal 
is stored, this is not likely to cause trouble. “ 

“Most important.” 

29. Avoid air channels in a coal pile such as occur about inbedded pipes, the 
bents of trestles, cracks through bulkheads, etc., since fires frequently orig¬ 
inate near such air channels. 

Comments: 

“Never had this trouble.” 

“Believe ventilating the thing after removing the heating.” 

‘ ‘ Are you sure that nails in the bents are without blame. ’ ’ 

“Have used pipes to permit circulation of air. Feel that this has done 
some good toward preventing spontaneous combustion.” 

“We have always used old boiler flues in storage piles in order to ascertain 
the temperature by hanging thermometers in them or by noting the haze 
which is visible on cold mornings and indicates heating.” 

“Inconsistent. Universal ventilation is a good thing.” 

“This also provides ventilation which will prevent firing.” 

“Wooden bents of trestles and other wood, partitions, etc., furnish an easily 
oxidizible substance.” 

‘ ‘ Our methods of preventing spontaneous combustion are principally as 
follows: The maintaining of a 25-foot bulkhead all around the two piles; one 
containing 250,000 tons of high volatile and the other 150,000 tons of low volatile 
coals. When coal is received early in the season it is stored so that it can be 
used first; or in other words, our object is to use the oldest coal first.” 

‘ ‘ Protect the pile by bulkheads or walls. My storage contains December 1, 
generally 200,000 tons, 225 feet wide, 40 feet high. On the east and west sides 
concrete walls 13 feet high protect the pile. The north and south ends are open. 
Our fires, when we had them, a few years ago always were on the north and south 
sides of the piles, never on the east and west sides.” 


Method of Piling Coal 

30. Unless coal can be piled so that air can thoroughly circulate through the 
pile and thus carry off the heat as rapidly as it is generated (this is very 
difficult to accomplish), the more closely fine coal is piled to exclude air 
the better. 


150 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Comments: 

‘ ‘ I have always believed that tight packing of coal through pressure produced 
heat. ’ ^ 

‘^It is impossible to carry off the heat generated in fine coal by any circula¬ 
tion of air.’’ 

think it is impossible to pile coal so closely as to exclude air- to any 
beneficial extent.” 

“Inconsistent. Universal ventilation is a good thing.” 

“Coal must be piled low enough so that the generated heat can be carried 
off without reaching the firing temperature. ’ ’ 

“To be dispensed with by favoring the subaqueous storage and is the only 
manner in which fine coal can be stored without hazard from spontaneous com¬ 
bustion. ’ ’ 

“Since the voids in fine coal of uniform size are about the same as the voids 
in course coal of uniform size, would it not be better to say mixtures of various 
sizes tend to reduce the void spaces and exclude air? ” 

Ventilation of Coal Piles* 

31. Ventilation of coal piles by means of pipes running through the pile has 
usually not been successful in preventing spontaneous combustion, because 
the air does not circulate freely throughout the pile and in some cases the 
air currents through these pipes seem to be starting points for fires.” 

Comments: 

“Several years ago, we were storing quite a large amount of Oklahoma mine 
run coal at Smithville, a coaling station which is located not far from San Antonio. 
I experimented with one pile of coal by placing a six-inch glazed tile on the bottom 
and running it the entire length of the pile. This tile was the ordinary bell 
shaped and in putting it together we used no cement, but just laid the ends to¬ 
gether. Along the side of this pile of coal I stored an equal quantity without 
using any tile. The result was that in the pile where I had placed the tiling, we 
had no fire whatever, but in the other pile where we had no tile we experienced 
considerable amount of trouble by reason of spontaneous combustion. I am of 
opinion that pipes or flues do not always produce the desired results.” 

“Ventilation by means of pipes has not been successful. Do not think these 
pipes are the starting points for fires. ’ ’ 

“Helps some.” 

“Heartily agree; think there has been a lot of misinformation put forth on 
this point.” 

“Have had no trouble with pipes. We think tendency is to carry away heat 
by radiation. ’ ’ 

“Such pipes are probably useless except to indicate or follow rise of tem¬ 
perature. ’ ’ 

‘ ‘ In two plants we have put in iron pipes to admit air but in the other where 
at least 12,000 tons are under storage, we have not taken measures to prevent 


* See page 32, for extended discussion of coal pile ventilation by J. B. Porter. 



THE STORAGE OF BITUMINOUS COAL 


151 


heating. I am of the opinion that we have as good results where no measures are 
taken as where we have the air pipes. 

‘ ‘ My personal opinion is that a cooling system employing extra heavy iron 
pipe and circulating water would be more satisfactory and certainly much safer, 
than any ventilating system that could be devised.’’ 

32. The great objection to ventilating systems is that they interfere with the 
handling of the coal. 

Comments: 

“Very expensive.” 

‘ ‘ They do not pay for the efforts. ’ ’ 

“Unless thorough not of much benefit.” 

“Great objection is that they do not work as intended.” 

33. There is great difference of opinion in regard to the height of piles in 
which coal may be stored safely. Coal seems to fire almost as quickly in 
low piles as in high and as often near the top or outside of a high pile as 
near the bottom. The principal disadvantage of high piles is that coal 
in them cannot be so readily removed. 

Comments: 

“I have always believed that the higher the coal is piled the more liability 
to fire through pressure.” 

“Height undoubtedly varies for every coal but for any coal low piles are 
safer and definite height can be established for any coal. Low piles lessen heat 
from pressure and make for safety.” 

“It is not our experience that coal fires as quickly in low piles as in high. 
It has been our experience that if the depth of the coal is limited to twelve feet 
ho fires will occur.” 

‘ ‘ After eight or ten feet there is no additional hazard because of increased 
height, and any increase of height within reach of the crane is not attended by an 
inconvenience in reloading the coal.” 

“If piled by hand piles should not be over ten to twenty feet wade, fifty 
feet long, though bottom of piles may touch. More space is required but it is 
safer. Piles may be much larger if mechanical handling is used.” 

^ ‘ High piles due to the greater pressure fired more readily than low piles. ’ ’ 
“Depends on the storage system.” 

‘ ‘ Think height should be limited to ten feet. ’ ’ 

“We pile from twelve to fourteen feet.” 

“Believe in low piles about eighteen feet high.” 

“The lower the pile the less liability to fire.” 

“High piles give more trouble.” 

‘ ‘ Think height is important factor, the greater pressure inducing heat. ’ ’ 

“Coal almost always fires near the bottom.” 

‘ ^ Height for safety depends on the kind of coal. ’ ’ 

“More fires from higher piles.” 


152 


ILLINOIS ENGINEERING EXPERIMENT STATION 


“If space is available pile low/' 

‘ ‘ Height of pile of- no consequence, excepting crushing effect. ’' 

‘ ‘ Height of pile is one of determining factors. Have proved this, this summer.'' 

‘ ‘ Depends entirely on method of storing. Low piles for hand, high for crane 
bucket.'' 

‘ ‘ Might be amended to the effect that the height to which coal is piled should 
be regulated to conform to the facilities for removing or reloading the coals from 
the piles." 

“Coal fires at the depth where enough air cannot penetrate and all of heat 
is not lost by convection to the atmosphere. This depth varies with the character 
of the coal." 

‘ ‘ We limit the height of piles to twelve feet and have had less difficulty from 
spontaneous combustion in low piles. Furthermore if piles are narrow, they are 
easier to handle in case of spontaneous combustion. 

Use of Water in Extinguishing Fires 

34. Water is not generally successfully applied in extinguishing fire in a coal 
pile, because it is impossible thoroughly to saturate the pile. A small 
amount seems to aid spontaneous combustion. 

Comments: 

“Nearly all bituminous coals contain considerable tarry matter which is 
distilled from the coals during the heating process before the coal actually ignites. 
These tar vapors rise and condense in the cooler coal above forming a crust of 
mixed tar, pitch and coal which water will not penetrate and therefore the fire 
cannot be reached by water from the top except possibly in spots." 

“We have extinguished several fires by applying water, cooling the coal for 
a distance of four or five feet, shoveling out the wet coal, then applying more 
water, cool another layer and shoveling that out and so on until we reach the point 
where the coal is either on fire or very hot." 

‘ ‘ This is not our experience. Have an 8-inch water line along the field 1300 
feet long and extinguish fire successfully with water." 

“Water is effective when applied directly to the fire after removal of euper- 
imposed coal.'' 

“We expose the heated coal to the air which reduces the temperature and 
extinguishes fire." 

“This agrees with our experience." 

“Depends on size of fire." 

“After getting to spot that is on fire water has to be used." 

‘ ‘ Fire must be dug out.'' 

‘ ‘ Whenever I had trouble with a bunker fire on board* ship I simply opened 
one of the deck scuttles and let in a hose until the compartment was fairly well 
filled with sea water. This appeared to be an easy and sure way of overcoming 
the fire." 

“Heated portion of pile can be cut off frequently by driving spray pipes into 
pile and flooding pile with water from fire hose connections which will retard fire 
and put it out sometimes.'' 


THE STORAGE OP BITUMINOUS COAL 


153 


Under-water Storage 

35. Tho deterioration in coal stored under water is negligible. Such coal 
absorbs little extra moisture. 

Comments: 

“Coal when stored under water absorbs considerable moisture, and in fact, 
becomes so wet that it is necessary for us to lengthen the coking time. ’ ’ 

“Only place to store slack or nut.“ 

36. With under-water storage if the entire coal pile is not covered, the part of 
the pile above the water line is liable to spontaneous combustion. 

Comments: 

“We would not suppose that submerging part of a pile would render the re¬ 
mainder immune, neither would we suppose that the exposed part would be more 
liable to fire.’’ 

“This liability is less than that with dry storage of depth equal to depth 
above water line. Believe the only practicable and reliable plan of storage to be 
with partial submergence. By this plan coal may be successfully piled twenty- 
three feet above the water line.” 

“Very readily. I assume capillary action and wetting of the pile.” 

37. The white coating on the outside of some coal piles is very thin and does 
not affect the value of the stored coal. 

Comments: 

“If not sold on looks as is often the case.” 

“Not appreciably.” 

38. The best method of handling coal in danger of firing is to load it out and 
scatter it so that it will be thoroughly cooled off. 

Comments: 

“If handy to point of consumption it can be put on the engine tank) or 
boiler house coal bin for immediate use after being thoroughly wet down. This 
will save the expense of rehandling.” 

“A uniform depth of four feet would probably not fire, and if a pile which 
contains fire were spread out to this depth, the fire could be extinguished with hose 
after which the coal, if not piled up again, would be safe.” 

“Does not always work with Mid-West coal.” 

‘ ‘ Turning pile over slowly will answer. ’ ’ 

‘ ^ If the scattered coal is well thinned out, water should be put on it. Handled 
7,000 ton pile of screenings this way this summer. ’ ’ 

39. Coal which has a tendency to spontaneous combustion should be turned 
over to keep down the temperature, although this causes an increase in 
breakage. 


154 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Comments: 

“Impracticable for railroads.” 

“This would probably be effective, although expensive. It need not be re¬ 
sorted to until the coal begins to gas. 

“Yes, but makes the expense of storing coal prohibitive.” 

‘ ‘ Do not disturb a pile at all once a pile has heated. It cannot be again 
stored. ’’ 

“Not necessary until heating commences. ’ ’ 

‘ ‘ Impracticable. ’' 

“Bad practice for Mid-West coal.” 

‘ ‘ Does not seem practicable for if the pile is a large one, say of 50,000 tons, 
the cost of turning it over frequently would be prohibitive. ’ ’ 

“This conclusion and the one following seem to be inconsistent with each 
other.” 

“Pile it low enough this will not need to be done. No experience turning 
coal over. ’ ’ 

‘ ‘ And soaked with water. ’ ’ 

‘ ‘ Questionable. ’ ’ 

“Yes, but once in six weeks or two months is often sufficient.” 

‘ ‘ Seems to indicate unusual difidculties in connection with storing coal and I 
am sure no one would undertake to store coal if it had to be turned over or 
moved frequently.” 

“On the Lake docks it is a common practice to move to another part of the 
dock, or to turn over a pile that begins to heat and which cannot be shipped out 
at once. This practice is diametrically contrary to the conclusion reached at one 
of the largest known storage plants for fuel coal. 

40. If possible, stored coal should not be moved until it is to be used, unless 
it is heating, since piles which have apparently been safe have taken fire 
when opened to the air and the coal moved elsewhere, probably because of 
the opening up of new faces for oxidation. 

Comments: 

‘ ‘ Doubtful. ’ ’ 

“Cut out unless it is heating.” 

‘ ‘ This looks doubtful; still I would leave it alone unless the temperature 
reaches the danger point about 150 degrees F. ’ ’ 

41 Coal which has once heated and cooled is not subject to the same oxidizing 
processes as fresh coal. 

Comments: 

“Not if it has heated long enough.” 

“Never.” 

“Not to the same extent, but nevertheless coal that has been scattered and 
thought to be cooled has fired. ’ ’ 

“One trouble is disintegration of shale seam or thin laminations of dirt and 
the pieces break up with handling or in firebox. ’ ’ 


THE STORAGE OF BITUMINOUS COAL 


155 


‘ ‘ Coal once heated has very little value for fuel purposes. ’ ’ 

'‘One of our mechanical engineers, W. L. DeBaufre, for about five successive 
years tested Pocahontas coal which had been stored at the New London, Conn., 
Naval Station in three different ways, namely, one part was stored under water, 
one part was stored on shore under cover, and the remainder was stored on shore 
not under cover. The test showed about the same evaporative value for each of 
these coals. If there was any difference it was in favor of the coal stored in the 
open, and the coal stored under water ranked next. Out at Cavite, in the Philippine 
Islands, the Navy Department has had considerable trouble with spontaneous igni¬ 
tion of its coal piles; but of course out there the sun is very hot and the days are 
long. Here at the Experiment Station we store our coal about twelve feet high on 
a concrete pavement, and so far w^e have had no trouble. ’ ’ 

"Practical railroad man hates storage coal. It is usually used the coldest 
season of the year when mines will barely produce enough steam; therefore, an 
85 per cent storage results in only 50 per cent good service." 

‘' Our trouble is disintegration of shale or their laminations of dirt and the 
pieces of coal break up with such handling and in the firebox. ’ ’ 

42. Coal which has been in storage is considered by many to burn less freely 
when fired in a furnace, but this is largely prejudice and can be-overcome 
by keeping a thinner bed on the grate than with fresh coal and by regulat¬ 
ing the draft. 

Comments: 

"It seems to us that the ingredients which would promote spontaneous com¬ 
bustion must also act as agents to promote free burning. ’ ’ 

"Have found fresh-mined coal always gives best results. It is proved that 
even coal mined from the pillars in mines is very inferior to coal taken from the 
rooms. ’ ’ 

"It is usually claimed that heat units are less. Never heard of it burning 
less freely." 

"We like a slow-burning coking coal." 

"No material effect." 

"Nothing in this." 

'' Coal frequently loses twenty per cent efficiency. ^ ’ 

' ‘ Should be saturated with water. ’' 

'' Actual experience indicates otherwise. ’ ’ 

"Due to absence of volatile." 

‘' Would burn less freely according to previous conclusion. ’' 

'' If volatile matter has diminished coal will not burn as freely. ’ ’ 

'' We have more trouble the longeft stored. ^ ’ 

"Not entirely prejudice. I believe it does not have the affinity for oxygen 
that fresh coal has." 

"We see no apparent difference." 

43. The decrease in heating value as a result of storing coal is small unless 
the coal has heated up sufficiently to decompose the coal or to drive off 
the volatile ingredients and the loss of moisture from the coal may increase 
the heating power per pound of coal. 


156 


ILLINOIS ENGINEERING EXPERIMENT STATION 


Comments: 

*‘Yes, depending on the length of time coal has laid in storage.’^ 

‘‘Never had this experience. Degradation first, then loss of volatile pulls 
down the value. 

“Our coal takes on moisture from storage.“ 

“But not of the original pound. 

“High burning rate on locomotives makes loss greater.^’ 

“Disintegration disturbs firing method on account of varying percentages of 
sizes in boiler house, coal bin and in firebox.’’ 

‘ ‘ This is a very debatable question and while tests show very litle decrease in 
the thermal value in the coal during storage, the fact remains that for a given 
pumpage of water, our coal consumption has increased by amounts varying from 
ten to sixteen per cent. The coal has lost its shiny appearance and as a consider¬ 
able portion of the volatile is lost, it does not act the same in our stokers as when 
freshly mined. ’ ’ 

‘ ‘ We find that by wetting the coal that has been in storage for some time, its 
burning properties have been enhanced, especially so in the case of smokeless 
coals. ’ ’ 

44, The coking properties of eastern bituminous coals are not materially affected 
by storing unless the coal heats, but the coking properties of Illinois and 
other Middle West coals are seriously affected or destroyed by storage. 

Comments: _ 

“As to the deterioration of coking properties in eastern coals, will say that 
some of them deteriorate rapidly while others do not. Eastern Kentucky is a 
marked instance of a coal that does not deteriorate very rapidly. The coking 
properties of Illinois and middle west coals are seriously affected.” 

“From conversation with by-product coking men, I gathered the opinion 
that the coking properties of all bituminous coals, including the Eastern, was af¬ 
fected by storage. Some coals to a greater extent than others.” 

‘ ‘ Have not noticed coking properties of Illinois coal to be affected by storage. 
We have about 15,000 tons in stock now and are using some that has been in 
stock over six months with no bad effect. ’ ’ 

“Omit the phrase ‘or destroyed by storage.’ ” 

“Yes, for eastern coals. No experience Illinois coal.” 

“Gradual absorption of oxygen by coal does slightly decrease its coking 
ability, even though the coal does not heat seriously, particularly true with 
western coals.” 

“It is said by many practical coke men that coking quality is generally 
impaired by long storage of the coal. It is claimed by many coke oven operators 
that weathering of some coal affects the contracting qualities of the coal during 
the coking and, therefore, a stored coal is more likely to stick in the coke oven. 
By-product yields, especially that of the gas, are probably lowered in a high 
volatile coal by long storage.” 

45. The best preventive of loss in coal storage is the constant inspection and 



THE STORAGE OF BITUMINOUS COAL 


157 


watching of the coal for incipient heating and immediate removal of coal 
from the spot affected. 

Comments: 

‘‘Isolated hot spots sometimes occur which can be readily dug out with a 
crane, leaving the remainder of the coal in good condition. The temperature of 
every pile will go up and down, influenced in part by the temperature of the sur¬ 
rounding air and in part by internal heating, but it -vYOuld be inexpedient to dis¬ 
turb the pile unless the temperature rises to near 200 degrees and is accompanied 
by the evolution of gas.” 

“Best preventive is properly storing it. Know your coal and store it low 
enough so that it will not fire. An inverted V-shape pile is preferable. ’ ’ 

“Proper selection of storage space, sizes stored, properly seasoned coal, man¬ 
ner of handling. Do not store mine run under any conditions and especially do 
not build up pile by carrying track upon pile. Recent experience of the Big 
Four shows that fire is sure to follow such methods.” 

“The real successful method of storing coal in this locality, Springfield, 
Illinois, has been under water. When piled on the ground should be in long piles 
with quantity limited as much as practicable. Would recommend only storage of 
screenings of fine coal and when this is done the only successful method has been 
under water.” 

“Place li^-inch pipes every sixty feet in pile and take interior temperature 
every 36-48 hours by lowering thermometer floating in mercury down the pipe, 
leaving it in the pile for about ten minutes. On large storage a mercury electric 
alarm system will pay.” 

“Give suggestions as to manner of “inspection and watching; i. e., should 
thermometer holes be built in piles for inserting thermometers in center of piles? 
What rise in temperature is considered dangerous? Examination of gases? Odors 
from pile?” 

46. Other Suggestions. 

Comments : 

“Use coal from the newer piles.” 

“Coal successfully stored for a year is usually past danger.” 

“No chemicals applied as for extinguishing other fires have any more effect 
than water (which is very little). The thing to do is dig into the fire and move the 
coal as quickly as possible.” 

“Successful storage depends on proper selection of storage space, sizes 
stored, storage of properly seasoned coal, and manner of handling. Do not store 
mine run under any conditions and especially do not build up pile by carrying 
track on pile, as recent experience of railroads shows that fire is sure to follow 
such practice.” 

Through the courtesy of Frank Haas, Consulting Engineer, Consolidation 
Coal Company, the following conclusions of that company regarding coal storage 
are given: 

(1) “Spontaneous combustion is not limited nor is the tendency greater 


158 


ILLINOIS ENGINEERING EXPERIMENT STATION 


with any one class of coal—referring now only to the bituminous coals ranging 
from sixteen to forty in volatile matter. 

(2) “The tendency is not in proportion to the quantity of sulphide present. 

(3) “In coals of the same kind (graded according to volatile matter) those 
which have the highest per cent of impurity are more liable to spontaneous com¬ 
bustion. 

(4) “In coals of the same kind, heating is more liable to occur in the fines. 

(5) “Weather conditions apparently have no effect (in this it should be 
explained that our records do show more on cold and wet days, but we have as¬ 
sumed for good reason that heating is more readily observed on such days). 

(6) “The coals with which we are familiar have never been known to fire 
inside the mines, either in the solid or in accumulations inside the mine. 

(7) “In stored coal quantity or depth of pile have evidently not much to 
do with it as we have found local heating to occur near the top as well as in the 
center or bottom of the pile. 

(8) “In our opinion, and we have numerous cases to substantiate it, a great 
number of local heating cases have been due to waste material brought out with 
the coal, such as pieces of wood, discarded clothing saturated with miners oil, 
waste, brattice cloth, etc. We do not hold exclusively to this for there still re¬ 
mains to be explained the slow propagation at a temperature far below that of 
normal combustion temperature of coal. 

(9) “We have many instances showing that more local heatings have oc¬ 
curred than were discovered, showing very small areas of activity and were 
spontaneously extinguished, indicating that propagation of heat is not inherent in 
average coal, but localized by some particular, perhaps foreign, condition. 


THE STORAGE OF BITUMINOUS COAL 


159 


APPENDIX III 


EXPERIENCES OE FIRMS AND INDIVIDUALS STORING COAL 

Many of the answers to the questionnaire sent to coal dealers and users have 
been incorporated in the preceding pages of general discussion, but there still 
remain a few specific instances of successful and unsuccessful attempts to store 
coals of many different kinds under various conditions which have not been dis¬ 
cussed. Available information relating to these cases is presented in the following 
paragraphs. In each case a brief statement of the conditions is given and while 
a certain amount of repetition is thus unavoidable, this method of presentation 
seems desirable for purposes of comparison. 

42. Storage for Domestic Use and iy Coal Dealers .—Personal interviews 
with coal dealers in Urbana and Champaign and answers received to the 
questionnaire indicate that there is no trouble in storing coal under the condi¬ 
tions which prevail in the ordinary coal yards and in dwelling houses. The loss 
from breakage in storing and reclaiming bituminous coal is 5 per cent or more, 
according to the coal and the method of handling. There is no loss in fuel value 
and consequently stored coal sells for the same price as fresh coal, although there 
may be a slight loss of weight due to drying out. 

The Crystal Ice and Fuel Company* of Danville, Illinois, stores coal from 
Harrisburg, Illinois, and from the No. 4 vein in Indiana during July and August, 
when the coal is cheapest and driest, in 65-ton covered bins with plank fioors. The 
period of storage is three months. The sizes are kept separate and the slack is 
not removed before storing. The coal is stocked by dumping and reclaimed by 
shoveling at a total cost of seventeen cents per ton. 

D. G. Porter, of the Rock Island Fuel Company, stores about 8,000 tons of 
l]^-inch washed coal from Springfield, Illinois. The coal is placed on the ground 
by hand and in continuous fiat top piles eight feet high, at a cost of eight cents 
per ton for stocking and ten cents for reclaiming. It is kept in storage for six 
months with no decrease in heating value unless the pile heats. The coal is 
stored in November and December to take advantage of cold weather so that the 
snow and ice will stay in the coal until late in the spring. The coal thus stored 
does not ordinarily heat for six months, but if heating does occur, it is loaded out 
and burned. 

The Beck Coal and Lumber Company of Harvey, Illinois, stores about 500 
tons of Pocohontas coal and 700 tons of Illinois coal for five or six months, the 
sizes being kept separate and slack being removed before storing. It is stored 
from fourteen to thirty days after mining and preferably in June, July, and 
August. There is no difference in the selling price of stored and fresh coal and 
no depreciation from heating occurs, but there is a loss of from two to eight per 
cent from breakage. If heating occurs the coal is moved. It is stored on the 
ground in bins from eight to ten feet high and reloaded by hand shoveling. The 
expense of unloading, storing, and reclaiming is 27.82 cents per ton. 


* Thomas Corsey, Secretary. 




160 


ILLINOIS ENGINEERING EXPERIMENT STATION 


O. S. Dodge and Sons, Incorporated, of Monroe, Wisconsin, store 1,200 tons 
which are mostly two inches by three inches nut coal from Franklin County, 
Illinois. It is stored in bins by elevators and run out by gravity. The different 
sizes are kept separate but the slack is not removed. There is no decrease in 
heating value, but a considerable loss through breakage. 

The Davenport Locomotive Works, Davenport, Iowa, report that 300 tons of 
2-ineh screenings from Franklin County, Illinois, are kept in storage on the 
ground in a continuous pile ten feet high, from three to six months with slight 
undetermined loss in heating value and no firing. 

French and Hecht, of Davenport, Iowa, stored washed Illinois pea coal in 
large quantities, either under cover or in the open without any firing, but they 
report that they always have trouble from fires in attempting to store unwashed 
screenings. 

The H. A. Hillmer Company of Freeport, Illinois, stores from 1500 to 2000 
tons of West Virginia egg, and Illinois and Kentucky lump and nut sizes on 
cement floors in a coal elevator in which there are five compartments thirty feet by 
thirty feet by fifteen feet, the coal being piled from ten to thirty feet high. It 
is stored and reclaimed by wheelbarrow and conveyor and if carefully handled 
there is little breakage. From five to fifteen days elapse between mining and 
storing and it is kept in storage six months, the sizes being kept separate. The 
slack is not removed and coal is preferably stored in April and May, because then 
the price is usually fifty cents less per ton than in other months, and since the 
year’s domestic business is about closed a force of men is available which may be 
employed in unloading the coal. The weather, moreover, is not too hot, whereas in 
July and August it is almost impossible to get men to unload coal. There is no 
difference in the selling price and no deterioration, for if the coal is kept under 
cover and dry there will be no heating, but if heating occurs the coal is removed 
and wet down. The expense of storage is not kept. 

I. C. Cuviller, publisher of The Coal Trade, Minneapolis, Minnesota, sum¬ 
marizes the storage problem for the city and coal trade as follows: 

In the domestic trade lump, egg and No. 1 nut from Williamson, Franklin 
and Saline counties are stored out of doors mainly on the ground in round py¬ 
ramidal piles of varying heights, about three weeks after being mined, and the 
coal usually is kept in storage from July to October. The sizes are separated 
and the duff removed. May, June, July, and August are considered the best 
months in which to store since the price is from 50 to 75 cents lower than at other 
seasons. There is no decrease in value and no difference in price of stored and 
fresh coal. The loss in breakage is thought to be about five per cent. Small 
amounts are usually stored in bins and fires are not common. When eastern coal 
is stored in large piles, it fires and the piles must be worked over and spread 
out. This is done usually by means of wheelbarrows but conveyors are being in¬ 
stalled. 

The Joseph Schlitz Brewing Company of Milwaukee stores West Virginia and 
Western Pennsylvania coals in continuous pyramidal piles fifteen feet high on a 
wooden floor with concrete walls during the season of lake navigation. There 
is little loss in heating value, and breakage is negligible since the coal is crushed 


THE STORAGE OP BITUMINOUS COAL 


161 


for use in stokers. The company does not buy high sulphur nor friable coals 
because of the tendency of such coal to heat. 

Crerar Clinch and Company* of Chicago keeps in storage, if possible, about 
15,000 tons of egg and nut. Nos. 2, 3, 4, and 5, washed and screened coal from 
Macoupin, Perry, and Jackson counties, Illinois. The coal is screened before 
storing and is placed in storage from one to two weeks after mining. Most of 
it is stored in July and August. The coal is used for steam purposes and there is 
no financial advantage in storing, the only difference in selling price being the 
added expense of storing. The coal is stored and reclaimed by hand or by a crane. 
It is stored on a plank floor in conical piles about sixteen feet high, and the sizes 
are kept separate. The coal is thought to decrease in heating value about five 
per cent and the large sizes to lose about ten per cent through breakage. The 
stored coal which has considerable sulphur in it heats within two or three weeks 
No precautions against heating are taken except to store in dry weather, and if 
heating occurs to turn the coal over or use it. It is estimated to cost twenty-five 
cents per ton to store and reclaim. 

The Ebner Ice and Cold Storage Company t, Vincennes, Indiana, keeps in 
storage several thousand tons of li/4-inch screenings from Fort Branch, Indiana, 
Wheatland, Knox County, Indiana, and Clinton County, Illinois. This coal is 
placed in a concrete pit arranged so that it may be flooded in a short time if it 
heats. A small amount of coal is also kept in storage on the ground. The coal 
is dumped from a trestle into a pit and is reclaimed by a bucket conveyor. The 
expenses are as follows: 



Storing 

Reclaiming 

Labor . 

Depreciation on mechanical equipment . 
Interest on investment.• . 

. $0.04 

0.03 

0.084 

$0.10 

0.03 

0.084 

Total. 

. $0,154 

$0,214 


The Polar Wave Ice and Fuel Companyt, St. Louis, Missouri, stores 20,000 
tons of screened lump coal from St. Clair and Williamson counties, Illinois. All 
the lump coal is forked into storage, the sizes being kept separate. It is stored 
within one or two weeks after being mined and is kept in storage from a few 
weeks to several years. It is stored during the dry summer months, when possible, 
and there is a slight decrease in heating value and a loss of from ten to fifteen per 
cent from breakage. Heating is more likely to occur in the open than under cover. 
Dried lump coal forked into a shed seldom heats, but wet coal will heat in time. 
It is stored by means of especially constructed chutes traveling on a trolley and 
by wheelbarrows, and is reclaimed by hand. It is usually placed on a brick or 
concrete floor in piles, about 10 feet high and from 30 to 60 feet wide, parallel 
with a railroad track. 


* A. R. Stooper, Yard Superintendent, 
t C. B. Wissing, Superintendent. 

$ John C. Muckerman, Vice-President. 










162 


ILLINOIS ENGINEERING EXPERIMENT STATION 


The expense of storage is as follows: 


Overhead .. 

Labor . 

Supplies . 

Depreciation on mechanical equipment 

and S. S. 

Interest on investment and coal . 
Insurance or equipment and sheds . 
Insurance on coal. 

Total. 


Storing Reclaiming 


$0.05 

$0.05 

.20 

.10 

.02 

.01 

.07 


.12 


.01 


.01 

• • * * 

$0.48 

$0.16 


In September, 1914, run of mine coal in the bin of the new high school in 
Urbana, Illinois, ignited and considerable difficulty was experienced in extinguish¬ 
ing the fire. The bin is 56 feet long, 12 feet wide, and 12 feet deep fed through 
two top holes. The walls are of brick, 8 inches thick, laid in plaster with about 
eight inches of air space between the storage bin and the wall enclosing the boilers. 
The coal stored was from Seam No. 6 from central Illinois and 200 tons of run of 
mine were placed in the bin within a few days after it was mined, the coal being 
wet down sufficiently to lay the dust as it was stored. The only separation of 
sizes was that due to the large lumps rolling down the sides of the cones while 
the fine coal formed the centers. The last load was placed in the bins June 29 
and five weeks later the coal was discovered to be on fire. The top charging holes 
and the bin door were covered as tightly as possible with tar paper, and CO gas 
was run into the bin which was then not opened until November 5. Two days 
after opening fire was again discovered. After partially flooding of the bin 
proved ineffectual, part of the coal was removed so that a hose could be played on 
the fire from the inside, but this plan did not prove effective and the heated coal 
was shoveled out. Similar trouble was experienced during the following winter, 
but since that time the practice of wetting down the coal when placed in the bin 
has been discontinued and an effort made to store only lump coal. Since this 
practice was adopted no trouble has been experienced. 

A similar fire occurred in the bunkers of the Champaign, Illinois, high school, 
where 500 tons of central Illinois coal were stored in May, 1917, the coal contain¬ 
ing considerable fines and the upper part of the pile being wet down when it was 
loaded into the wagons to be hauled to the bins. Toward the end of October smoke 
was discovered coming from the pile, which was then wet thoroughly by the fire de¬ 
partment. About 20 tons were loaded out from the top of the pile and a hot spot 
found from four to five feet from the top. The surrounding coal was then taken 
out and no further trouble has been experienced. 

The Northwestern Fuel Company*, St. Paul, Minnesota, stores, 50,000 tons 
of West Virginia and Maryland lump, egg, nut, and run of mine and one million 
tons, or more, of Pennsylvania, Ohio, West Virginia, and Kentucky lump, run of 
mine and screenings. Slack is sometimes removed at the mines, but not at the 


* G. H. Hutchinson, Chief Engineer. 













THE STORAGE OF BITUMINOUS COAL 


163 


dock, and sizes are kept separate in storage when they are so delivered to the dock. 
There is thought to be a slight decrease in heating value and a loss from breakage 
which varies widely with the conditions of handling. If the bituminous coal 
heats, it is usually within one to six months, according to the kind, character, and 
size of coal. To prevent heating, the coal is shipped out as promptly as possible, 
or if heating occurs, it is moved by a clam-shell bucket and bridge. The loss 
through heating varies from slight to complete destruction according to the extent 
of the heating. The coal is stored on a plank floor, which is laid on sand filling. 
It is placed in continuous piles from 33 to 55 feet high. If possible, the coal is 
piled to prevent large sizes rolling to the bottom. There are from 20 to 75 per 
cent fines below ^ inches when the coal is stored. 

The Consumers’ Company* of Chicago stores 250,000 tons or more of bitu¬ 
minous coal and a similar amount of anthracite, the bituminous being mainly 
Illinois and Indiana coal larger than the No. 4 washed. Some Pocahontas mine 
run is also stored. At times, portions of the stored coal are not moved for several 
years. In the larger bituminous storage yards, the coal is stored by a locomotive 
crane and grab bucket. The plat of Yard 150 (Fig. 58) shows a typical storage 
yard. The coal is stored about 26 feet high in piles, the shape of which depends 
upon the shape of the available storage space. The expense of handling depends 
upon conditions. Ordinarily, the coal is not insured against fire. 

The experience of the Consumers’ Company is that screenings below 1% 
inches in size will fire and that size No. 5 washed coal will fire even more readily 
than screenings, but that sized coal above inches from which the duff has been 
removed will, in general, stock without firing. Firing will start more quickly if 
wood is present. The leg of a trestle or a similar piece of wood will act as a flue 
and firing is likely to start near any such wood imbedded in the coal pile. High 
sulphur coals are thought to fire more readily than others. Ample flooding with 
water will put out a fire, but a small amount will accelerate the fire, and the best 
way is to turn over the pile. 

The St. Bernard Mining Company t of Nashville, Tennessee, stocks a great 
deal of 2^-inch bituminous lump coal in square piles on the ground to a height of 
20 feet. The coal is stocked by dumping from wagons and is reclaimed by fork¬ 
ing. The expense is ten cents per ton for labor and twelve cents for all other 
items, a total of twenty-two cents per ton. The coal is placed in storage from 
three to six days after being mined and remains in storage for about nine months. 
The best time for storing is said to be September and October, because then it is 
dry and cool. The coal is stored to protect contracts of the company and to in¬ 
sure a domestic supply. Storage is not profitable, but it is done as a precau¬ 
tionary'measure. The coal stocked is to be used for steam and domestic purposes 
and there is no difference in the selling price of the fresh and stored coal. It is 
estimated that a loss of twenty-five per cent in breakage has resulted in storing 
and reclaiming. In 1900 the Company had a bad fire in its storage pile. The 
next year enough air shafts, which were 12 inches by 12 inches and of 2-inch oak, 
were placed around the posts, which supported the shed, and connected at the 
bottom by troughs to give circulation of air through the pile. Since that time, 

* F. J. Hibbs, Superintendent of Construction. 

t .J. B. Love, Manager. 



164 


ILLINOIS ENGINEERING EXPERIMENT STATION 



< 9 / 1 ^ )fJDj qwo^ 


Fig. 58. Typical Storage Yard of the Consumers’ Company, Chicago 




























































































































THE STORAGE OF BITUMINOUS COAL 


165 


there have been no fires. Where the troughs rest flat on the ground, auger holes 
are bored to permit the air to circulate, but sometimes they are raised by blocks 
from two to four inches high to give circulation. As much as 8000 tons have been 
stored in this shed, but usually not more than 6000 tons. No fires have occurred 
since the flues were installed, but J. E. Love says: 

There might be some other reason for the fire that we had at the be¬ 
ginning of our operation as it started where we dumped the first coal, which 
had about a 20-foot drop and was badly broken and made a large amount of 
slack or dust. The next year, in addition to putting in the air shafts, we were 
very careful to build up the coal from the ground about 15 feet, so as to 
break the fall of the first coal that was dumped into the shed. I am not in a 
position to say for certain, whether the different method of handling the coal, 
or the air shafts, has kept us from having any hot coal after the first year. 

W. D. Langtry says in this connection: 

‘'Eecently I investigated a storage pile in Michigan at a plant which 
had the idea of putting down pipes for ventilation. In one instance there was 
one pipe that was a little taller than the balance, and I found by blowing 
some cigarette smoke over the top of the short pipe that this smoke was 
carried into the pipe by the draft, and the taller pipe was conducting the 
gases out of the pile and any smoke that was blown across its top was natur¬ 
ally conveyed up. It was plain to be seen that this was a current of air pass¬ 
ing through the coal. If this was sufiicient to keep the coal cool no trouble 
would occur, but from the gases being given off, I am afraid the air current 
was deficient.’^ 

The Pittsburgh Plate Glass Company,* Crystal City, Missouri, stores 40,000 
tons of mine run coal from Franklin and Williamson counties,* Illinois, on the 
ground in continuous pyramidal piles twenty feet high without having the slack 
removed. A Browning clam-shell locomotive crane is used to store and reclaim 
the coal and the expense is said to be twenty-five cents to store and twenty-five 
cents to reclaim. Storage during the summer is considered the best. The coal is 
kept in storage from two to three years, with a slight decrease in heating value. 
The coal may heat at any time after storage, and if so it is moved to another place. 

43. Light, Heat and Power Companies .—Public utility companies operate 
under the necessity of maintaining continuous service and are, therefore, vitally 
interested in the storage of coal. Many of these companies have already given 
considerable attention to the subject. 

The Eockford Electric Companyf, Eockford, Illinois, stores about 8,000 tons 
of 1%-inch screenings from Harrisburg, Illinois, on the ground in continuous 
pyramidal piles twenty feet high. The coal is placed in storage within about two 
weeks after being mined and is kept there for a period of six months. The coal 
may heat after two months and if so, it is turned over with a crane, but an effort 
is made to keep it from heating by ventilating with pipes. If the coal dries out 
and heats to any considerable extent, it is thought to^ deteriorate from twenty to 
fifty per cent. It is reported that it costs ten cents per ton to place it in storage 
and ten cents to reclaim it. 


* E. C. Taylor, Superintendent, 
t Adam Geschwindt, General Manager. 



166 


ILLINOIS ENGINEERING EXPERIMENT STATION 


The Wisconsin Gas and Electric Company,* Eacine, Wisconsin, stores 30,000 
tons of washed mine run Youghiogheny coal in a continuous pyramidal pile thirty 
feet high. The coal is stored on the ground by means of a bridge and bucket at an 
expense of eight cents per ton for storing and twenty-two cents per ton for re¬ 
claiming. This includes labor, supplies, depreciation on mechanical equipment, 
interest on investment, and rental of the land on which coal is stored. An interval 
of three or four weeks elapses between mining and storing. The coal is used for 
making city gas and it is thought to suffer a slight deterioration in value for that 
purpose. It sometimes heats in from two to four months in which event it is 
quenched with water and worked over. 

The United Kail ways Company t of St. Louis keeps in storage as much as 
5,000 tons of central and western Illinois screenings and mine run. These sizes 
are kept separate in storage but the slack is not removed. The coal is stored in 
bins and in piles on the ground about ten feet high with a locomotive crane. It is 
placed in storage about three days after leaving the mines and is kept there about 
three months in hot weather. The financial advantage of storing is regarded as 
doubtful. The coal is used for power purposes and little deterioration in heating 
value is noted unless firing takes place. The lumps are said to break up, but at 
this plant the coal is crushed before firing. The coal frequently heats and the 
time of heating is said to depend on the nature of the coal and on the weather. 
When heating begins, the coal is, if possible, removed and used. 

The Aurora, Elgin and Chicago Eailroad Companyt keeps in storage from 
2,000 to 15,000 tons of coal from Franklin and Williamson counties, Illinois. The 
coal is stored on the ground in piles eighteen feet high, each pile containing about 
six hundred tons. This has been decided upon as a safe size of pile to avoid heat¬ 
ing. The coal is stored with a crane and clam-shell bucket and is placed in stor¬ 
age about one week after being mined. The slack is not removed but the sizes 
are kept separate. The coal is kept in storage for periods as long as one year. 
Winter is regarded as the best time in which to store, but because of the availa¬ 
bility and price of coal in the summer most of it is stored between July and 
September. The reason for storage is mainly to prevent a shortage, but there is 
also said to be a saving of from thirty to fifty cents per ton by storing in the 
summer. There is considered to be a differential of fifteen cents per ton in the 
selling price against stored coal, which is thought to decrease in heating value 
from ten to twenty per cent. It has been the experience of this company that 
coal high in sulphur is not suited to storing, but, if stored, should have the slack 
removed and should be screened. It is reported that low sulphur coal, such as the 
best from Franklin and Williamson counties, stores well in any size and does not 
heat or deteriorate to any considerable extent for a period of several months. 
Certain coals from the same field, however, have heated after less than a week in 
the bin. Gillette is convinced that the amount of sulphur in the coal is a determin¬ 
ing factor in heating. He says: 

“Some three years ago we had about 10,000 tons of Cuba screenings 

on the ground. This coal started to fire from the inside and before we were 

* D. E. Callender, General Manager. 

t W. E. Bryan, Superintendent. 

t E. S. Gillette, Electrical and Mechanical Engineer. 



THE STORAGE OF BITUMINOUS COAL 


167 


able to pick it off the ground the majority of it had deteriorated about twenty 
to forty per cent in heat value, leaving some three cars of ashes which could 
not be run through the plant at all and consequently were a total loss. This 
coal had a high sulphur content. 

‘‘Since then we have piled our coal in small separate piles. We aim to 
put from twelve to sixteen cars in one pile. If we notice a fire starting in 
one of these piles, we immediately pick it up with a crane. Since we have 
started this system we have had practically no trouble from firing of our 
coal. ’ ’ 

John Hunter, chief engineer of power plants. Union Light and Power Com¬ 
pany, St. Louis, Missouri, says: 

“For the past ten years the miners’ and operators’ agreement expired 
every two years, and anticipating a strike at such time our local industrial 
and central station plants usually protected themselves by storing coal for 
at least thirty days. In 1912 our company stored about 30,000 tons of coal, 
and I am enclosing herewith a photograph (Fig. 59) showing one of the piles 
of 25,000 tons of mine run from the Mt. Olive and Staunton mines in Madison 
County. The coal was stored in February and March and was entirely re¬ 
moved and used by June 1. It was laid on the pile by hand and the track 
raised as the height of the pile increased, and was reloaded with a steam 
shovel from the pile into cars. We paid the Litchfield and Madison Railroad 
Company ten cents per ton to pile the coal and an equal amount to reload 
it, and it is my understanding that this figure just about covered the actual 
expense. After the coal was reloaded it was immediately shipped to our 
power station at Ashley street in St. Louis, placed in our bunker and used 
up in fifteen days. 

“We experienced two fires in this pile after it had been on the ground 
for two months. These fires were checked by working into the pile with our 
steam shovel and loading the coal in steel cars; about twenty cars in all were 
removed in this way. 

‘ ‘ The coal generally used by our company is from the mines in Macou¬ 
pin, Madison and St. Clair counties, ninety-five per cent of it being screenings. 
The only regular storage we have is in the coal bins directly over the boilers 
in the main central station. These bins have a capacity of 12,000 tons with 
an average operating storage of 7,000 tons. The bins are divided into eight 
sections, and it is necessary to have one of these bins working down for 
cleaning and reloading, otherwise extensive fires are very troublesome. The 
average temperature below these bunkers is about 125 degrees, and we find it 
impossible to carry the coal longer than two months, in other words, it is 
necessary to renew the coal in each of our bins every two months. 

“In the fall of 1911 I personally knew of one of the mine operators in 
St. Clair County laying on the ground the screenings from their mines, about 
30,000 tons in all, with the view of holding them in storage for the anti¬ 
cipated strike on April 1, 1912. However, in February of that year I ex¬ 
amined this coal and found that over eighty per cent of it had burned, the 


168 


ILLINOIS ENGINEERING EXPERIMENT STATION 


high percentage of sulphur, clay and other impurities being responsible for 
these fires. 

“It is a common expression among the engineers in our locality who are 
handling coal that it is impossible to store any of the standard coals from 
the inner group of mines in Madison and St. Clair counties, this being my 
personal views, unless the coal is specially selected. By this I mean that no 
coal of less than six-inch sizing be laid on the ground. ’ ’ 

W. E. Bryan, of the United Railways Company of St. Louis, says: 

‘ ‘ We try to decrease our storage in hot weather on account of the danger 
ible to firing than other coals. It has also been our experience that coal 
which has been cleaned by washing, say of nut or pea size, will not fire so 
readily as the screenings containing so much dust. The hotter the weather, 
the more is the tendency to heat. Also wet weather in connection with sul¬ 
phurous coal exposed to the air will cause heating especially when followed 
by hot weather. 

“Three months is the average length of time coal is in storage at one 
plant, which has a regular storage house. We do not make any tests for 
heating and as a rule have no trouble if the coal is not stored more than 
three months. We have stored the coal longer than this without trouble, but 
we do not like to carry more coal than can be moved in three months. 

‘ ‘ We try to decrease our storage in hot weather on account of the danger 
of firing and in the past have been stocking up to some extent in the fall 
when screenings are comparatively cheap. Under these conditions we may 
at times hold the coal in storage longer than three months. 

“It is hard to give any definite figures because our results have varied 
quite a good deal.” 

The Laclede Gas Light Company* of St. Louis stores from 5,000 to 15,000 
tons of Pocahontas screenings and from 40,000 to 85,000 tons of run of mine coal 
from Elkhorn, Kentucky. The sizes are not kept separate and slack is not re¬ 
moved before storing. It is stocked from seven to ten days after being mined 
and preferably in the spring or summer. No decrease in heating value is noted and 
there is no less from breakage. The Pocahontas coal heats in about six months. 
To prevent heating the piles are turned over, but if heating occurs the pile is 
quenched with water and used as soon as possible. Heating causes a loss in gas 
and in by-products. The coal is stored by means of a locomotive crane and clam¬ 
shell bucket. It is similarly reclaimed directly from the pile. The coal is stored 
directly on the ground in long, continuous piles from twenty to forty feet high. 

The Cleveland Illuminating Company keeps about 15,000 tons of slack, 85,000 
tons of run of mine Ohio No. 8, western Pennsylvania, and Fairmont, West Vir¬ 
ginia, coals in storage, the sizes being kept separate. The coal is stored by 
means of a gantry crane hoist in rectangular, continuous piles to a height of 
thirty-five feet and is recovered by means of a locomotive crane which handles 
about 500 tons in ten hours, the hoist handling about 1200 tons in ten hours. 

The East St. Louis Light and Power Company stores from 5,000 to 12,000 
tons of screenings under water from St. Clair and Madison counties, Illinois, as an 


* J. F. Bulfin, Auditor. 




Fig. 59. Twenty-five-Thousand-Ton Pile of Run of Mine Coal Stored by the 
Union Light and Power Company, St. Louis, Missouri 



S' ^ 7 



THE STORAGE OF BITUMINOUS COAL 


171 


emergency supply. There is no loss from breakage or depreciation in heating 
value. 

44. Stoi(if/6 at M^ctoJluTfficdl Plttnts .—According to the latest reports of 
the U. S. Geological Survey, there are more retorts for smelting zinc in Illinois 
than in any other state. This number has gradually increased and much of the 
smelting of zinc formerly carried on in Kansas, owing to the presence of natural 
gas, has within a few years been transferred to Illinois on account of the adequate 
coal supply. It is of especial interest, therefore, to note to what extent coal is 
being stored at the zinc plants. The following is a resume of the answers given 
in response to the questionnaire sent to the ten zinc smelters in the State. 

The Illinois Zinc Company at Peru and the Matthiessen and Hegeler Zinc 
Company at LaSalle operate their own mines contiguous to the smelters and do 
not store. 

The Sandoval Zinc Company at Sandoval and the Missouri Zinc Company at 
Beckemeyer do not store coal. 

The Collinsville Zinc Company at Collinsville stores No. 4 and No. 5 mixed 
Franklin County coal on the ground in continuous piles from ten to twelve feet 
high, in order to assure a supply for continuous operation. The coal is thought 
to decrease in heating value, but the amount of this decrease is not known. Coal 
is stored and reclaimed by hand, and no heating has been observed. 

The American Zinc Lead and Smelting Company of St. Louis, at its plant in 
East St. Louis, keeps in storage on the ground from thirty to sixty days 200 cars 
of St. Clair County, Illinois, run of mine coal without removing the slack. Coal 
is unloaded by locomotive cranes upon conical piles ten feet high. Cranes are 
also used for reclaiming the coal and while the storage costs are not segregated, 
they are estimated to be twenty cents per ton for placing the coal in storage, and 
fifteen cents for reclaiming. These figures include interest on the investment, re¬ 
pairs of unloading machinery, and all charges. The coal is used for making pro¬ 
ducer-gas and is stored to insure a supply at all times, but no financial advantage 
is secured. The coal is thought to decrease in heating value from about five to 
ten per cent. No data are available concerning breakage. Some kinds of coal 
fire, the time of firing after storage depending on the size and the sulphur content 
of the coal. As soon as heating is noticed the coal is picked up and used. Little 
time elapses between mining and storing. Winter is considered the best time to 
store. 

The Mineral Point Zinc Company at Depue, Illinois, stores coal in continuous 
piles from 600 to 700 feet long, 60 feet wide, 12 feet high, the piles being parallel 
with two tracks on which the locomotive crane and cars operate. The storage 
yard has a capacity of about 60,000 tons. Grab buckets are used and the expense 
of storing is from five to six cents and for reclaiming from five to six cents per 
ton for labor, materials, maintenance, and overhead. Coals principally from 
Harrisburg, Saline County, Illinois, are stored and they are kept in storage from 
six to twelve months. Lump or mine run is preferred. Screenings are kept in 
storage from one to three months, the different sizes being kept separate, but 
slack is not removed. The coal is stored in from five to ten days after being 
mined, mainly in the fall in anticipation of the spring needs but some coal is kept 


172 


ILLINOIS ENGINEERING EXPERIMENT STATION 


in storage at all times to insure against strikes and transportation trouble. Coal 
used for fuel and gas making purposes is thought to deteriorate in heating value, 
but no definite data are available. Screenings from southern Illinois heat in 
about ninety days, those from the Peoria district in about twenty-five days. From 
20,000 to 25,000 tons of mine run, lump, egg, and washed nut from the Peoria 
district are kept in storage at all times and no firing has occurred, although the 
piles are of the same size as those of the screenings. It is reported that a pile of 
Peoria run of mine has been in storage for a year without firing, the pile being 
twelve feet high, thirty-five feet at the base and containing about 3,000 tons. 

J. H. Brooks, Superintendent of the Depue plant, says that the slack is 
sometimes received hot in the cars and he believes that while a shallow pile will 
help to prevent the firing of unwashed Illinois screenings to a certain extent, his 
experience is that this class of coal cannot be stored for an indefinite period on 
the ground. As soon as heating is discovered the coal is loaded out. 

The Eobert Lanyon Zinc and Acid Company* of Hillsboro, Illinois, stores 
about 2,000 tons of run of mine Montgomery County, Illinois, coal from which 
the slack has been removed. It is stored in five to seven days after being mined 
and is kept in storage from three to six months. The coal is used for steam and 
gas making purposes and is stored to insure supply, with no financial advantage 
resulting. It is thought to decrease two per cent in heating value and it some¬ 
times fires in from one to nine months, the injury from firing depending upon the 
extent of the fire. Piles are continuous, fifty feet wide and five feet high, and are 
placed on the ground or preferably on cinders. To prevent firing the piles should 
be kept low. 

45. Storage for CoTce Ovens and Blast Furnace Plants .—The coal required 
for coke and blast furnace plants is so great that a considerable quantity is al¬ 
ways kept in storage to meet emergencies. Storage also makes it possible to take 
advantage of lake transportation. 

A number of coke and steel companies operating in the Chicago and St. Louis 
districts, and in other districts in the Middle West stores coals both from the 
Middle West and from the East. 

The By-Products Coke Corporationf of South Chicago keeps in storage a 
maximum of about 400,000 tons of miscellaneous sizes of West Virginia coals 
made up of about 160,000 tons McDowell Big Sandy coal and 240,000 tons of 
Kingston coal from Fayette County. Coals of different varieties are separated, 
but no attempt is made to separate sizes. The coal is piled on a 4-inch timber 
flooring in pyramidal piles from forty to fifty feet high by means of a belt con¬ 
veyor operated on movable bridges. It is reclaimed by buckets. The costs are 
not available since they are not segregated. Although the company stores large 
quantities of coal in the summer when lake transportation is open, it is considered 
best to store in the winter so that there may be less initial heat in the pile. In 
stocking an effort is made to avoid segregation of lumps in the pile. The coal is 
believed to deteriorate in heating value, but no data are available. After the coal 
is in storage four months, it is turned over to prevent heating. The coal some- 

* R, M. Roosevelt, Manager. 

t W. H. Allen, Superintendent of the Coke Plant. 


THE STORAGE OF BITUMINOUS COAL 


173 


times heats in from three weeks to three or four months in which event it is used 
up promptly or is turned over upon fresh piles. 

The Inland Steel Company* stores at Indiana Harbor 70,000 tons of run of 
mine and slack coal from a district north of the Pocahontas region in West Vir¬ 
ginia, and 140,000 tons of ^-inch Youghiogheny lump coal. The coal is stored 
from ten to fourteen days after mining. The slack is not removed and the sizes 
are not kept separate. The greater part is kept in storage from December 1 to 
April 15, while lake transportation is closed, and some remains in storage two or 
three months longer. It is stored on a 3-inch maple floor in a continuous pile 
forty feet high by means of a traveling bridge and belt conveyor. When the stor¬ 
age season opens, the floor is cleaned and coal is stored gradually from one end to 
the other of the pile. Coal is reclaimed by means of buckets, the coal longest in 
storage always being taken out first. August and September are considered the 
best months in which to store since the coal received then is dry. The heating 
value of the coal is not determined, but the gas made from the stored coal does not 
vary materially in heating value from that made from fresh coal. Coal sometimes 
heats and. fires in from a few weeks and to prevent heating it is turned over 
occasionally. If heating occurs, the affected part is removed. Coal thus heating 
loses its coking qualities. 

The Illinois Steel Company! keeps in storage at the Joliet Works from 10,000 
to 30,000 tons run of mine Pocahontas and from 10,000 to 30,000 tons of coals 
from Letcher and Harlan counties, Kentucky. Coal is piled twelve feet deep oy 
means of bridge and conveyor in concrete pits having concrete floors. It is stored 
within one or two weeks after mining and is kept in storage from one to twelve 
months. The coal may heat to a variable degree in from sixty to ninety days and ’ 
and if heating occurs it is taken out of stock. 

The Illinois Steel Company f also stores at South Chicago, Illinois, quantities 
as great as 100,000 tons of coal from McDowell County, West Virginia, and 100,- 
000 tons from Letcher County, Kentucky. The grade is run of mine and the slack 
is not removed. The coal is stored in the summer and within two weeks after 
being mined. It is used to make by-product coke. Coal is stored in a concrete 
bin in continuous piles fifty feet high. It is stored and reclaimed by means of 
overhead bridges. 

The Wisconsin Steel Company of South Chicago does not stock in large quan¬ 
tities and keeps only from 4,000 to 10,000 tons in piles which are being constantly 
drawn upon. 

The Iroquois Iron Company^ of South Chicago keeps about 1,000 tons of run 
of mine coal from Christian County, Illinois, in storage for about eight months. 
The coal is stored within two or three weeks after being mined and the slack is 
removed before storing. It is placed on the ground in a continuous pile twenty- 
five feet high by means of a locomotive crane at an expense of ten cents per ton 
for storing and reclaiming. The coal is used for steam purposes and it does not 


* H. D. DeHoll. Superintendent of the By-Product Coke Ovens, 
t D. R. Mathias, General Superintendent. 
t W. P. Gleason, General Superintendent. 

H Perrin Rule, Superintendent. 



174 


ILLINOIS ENGINEERING EXPERIMENT STATION 


depreciate materially in heating value, but suffers a loss of five per cent in break¬ 
age. 

The Coal Products Manufacturing Company* of Joliet, Illinois, stores about 
5,000 tons of run of mine from the Elkhorn and Logan Coal Company, West Vir¬ 
ginia, and 3,000 tons of run of mine from Franklin and Williamson counties, Ill¬ 
inois, for a period of from 60 days to 90 days. The coal is stored, within a week 
or two after mining, on the ground in separate piles, thirty feet high by means 
of a bridge which is also used for reclaiming. The coal is used for the manu¬ 
facture of by-product coke and no decrease in heating value has been noted. The 
Pocahontas coal heats within sixty days, but the Logan County coal has not done 
so. Heating is said to impair its coking qualities. 

The Jones and Laughlin Steel Company t of Woodlawn, Pennsylvania, keeps 
in storage 100,000 tons of raw Pennsylvania No. 5 coal all of which is passed 
through a three-inch crusher, also 200,000 tons of washed Pennsylvania No. 5 
which is passed through a %-inch crusher. The coal is stored in pyramidal piles 
300 feet wide and 350 feet long by means of a bridge and conveyor and is re¬ 
claimed by buckets from the bridge. The coal is stocked within three days after 
being mined and most of the washed coal is kept separate and left in storage for 
a period varying from four to eighteen months. The washed coal is stored at any 
time during the year, and the raw coal in November and December because of 
river navigation. The raw coal will fire spontaneously after about four months, 
starting about eight feet from the bottom of the pile, but while the washed coal 
heats up it does not fire. The raw coal is now piled only twenty feet deep instead 
of forty-five feet as formerly, and the washed coal is stored to a depth of forty- 
five feet. 

Horace C. Porter of the H. Koppers Company of Pittsburgh says: “We 
have noted especially in the plant of the Lehigh Coke Company, South Bethlehem, 
Pennsylvania, now owned by the Bethlehem Steel Company the fact that the 
weathering of coal in the open has a considerable effect on its coking qualities 
after a certain period and affecting the degree of shrinking or of expanding of 
the coal during coking.’^ 

G. F. Downs, Superintendent of the Lackawanna Steel Company, Buffalo, 
New York, says: 

• 

“Our experience in stocking coal has been that any low sulphur coal, 
such as Pocahontas coal, can be piled to a height of thirty to sixty feet and 
will stand indefinitely without heating or firing. 

“It is our experience that coals containing one per cent of sulphur and 
more cannot be piled higher than twelve to fifteen feet without heating and 
firing inside two months. We have tried piling such coals tv^enty to thirty 
feet high and using ventilating pipes, well distributed over the surface of 
the pile, but this gave no relief from the heating and we believe made the 
fire more rapid after it had once started as the pipes acted as flues.” 

The Calumet and Hecla Mining Company, t Calumet, Michigan, stored a max- 

* A. H. Harris, Superintendent. 

t A. W. Belden, Superintendent, Coke Department. 

J James McNaughton, Vice-President and General Manager. 



THE STORAGE OP BITUMINOUS COAL 


175 


imum of 500,000 tons of coal from Thacker, West Virginia, and Mansfield, Penn¬ 
sylvania, for a period of eight months, the coal being received within about two 
weeks after being mined and during the open navigation season from May to 
November. There is some depreciation in heating value but no material loss from 
breakage. If screened, there is no trouble from heating. The co^l is stored both 
in sheds and in the open in continuous rectangular piles about twenty-five feet 
high. A tower system of storage is now being installed. About ten per cent of 
the coal is below three-fourths inches. Sizes are not kept seperate in storage, but 
slack is removed. The expense of unloading from boats and storing is 15 cents per 
ton and the total reclaiming expense is 7^2 cents per ton in summer and 11^ in 
winter. These amounts do not include rent, interest, or depreciation. 

46. Mine Storage .—The simplest method of storage at the mine is by means 
of bins which form a part of the tipple structure or are located in a detached shed 
or building. Such bins provide a small storage capacity which will tide over any 
short stoppage of the mine and at mines where there are coke ovens and where it 
is necessary to insure a steady supply of oven coal they are extensively used. In 
the Pocahontas region of West Virginia, bins were at first built to take care of 
the slack only, but the system has gradually been extended to include all com¬ 
mercial sizes. In the Connellsville district of Pennsylvania the storage bins hold 
usually from 1000 to 2000 tons and permit the mines to be idle for a period of 
one day without interfering with the operation of the ovens. At some of the 
mines of the Middle West, particularly where coal is rescreened or washed, similar 
bins are used, but they are generally placed in a separate rescreening structure. 
The capacity of bins varies from 30 to 250 tons each and while they furnish 
small temporary storage for the washing or rescreening, they do not materially 
effect the operation of the large modern mines. 

The Federal Coal Company of Straight Creek, Kentucky, recently built at 
the Barker mine a storage bin which holds 150 tons of run of mine coal. The 
purpose of this bin is to furnish storage for at least a part of a day’s run in case 
cars are not placed at the mine, or in case there are not enough cars for the day’s 
supply. With regard to this bin R, R. Atkins, Superintendent, says: 

‘ ‘ We selected for the site for the storage bin, an old slate dump which 
was near our tipple and when dumping into the bin cars are shoved up a 
short grade to the top of this dump, about 15 feet above the dump at the 
tipple, and straight run of mine is placed in the bins, which have a gate at 
• the bottom for discharging into railroad gondolas. This has proved to be so 
successful that we have plans under consideration for erecting bins at our 
other mines to be used in a similar way, but we do not contemplate the stor¬ 
age of coal in any quantities. It is our idea to build bins of such capacity 
that the size of the bin, together with the mine cars at each mine, will hold 
about a day’s run. We believe that by doing this, we will be able to run 
our mines when we have no cars and also to load out a greater number of 
cars on days when the railroad places them, thus increasing our ear allot¬ 
ment. 

“While it is rather diflicult for us to figure on the exact price of dump¬ 
ing the coal in this bin, and discharging it, we figure that the additional cost 


176 


ILLINOIS ENGINEERING EXPERIMENT STATION 


amounts to about ten cents per ton. This could be considerably lowered by 
the erection of a bin of a different type but this would necessitate a greater 
expenditure of money in the erection of a bin as this bin was an experiment, 
we did not at the time feel justified in going to too heavy an expense.’^ 

Detailed descriptions of two plants for storing coal at the mines in Franklin 
County, Illinois, are given on pages 51 and 71, and for the large plant of the 
Clinchfield Fuel Company on page 64. 

The Bell and Zoller Company at Zeigler, Franklin County, Illinois, during 
the winter of 1916-17 stored 45,000 to 50,000 tons of Nos. 3, 4, and 5 coal by 
means of a 1 14 -ton clam-shell bucket operated by a locomotive crane. The coal 
piles were from forty to fifty feet long and thirty feet high, and the three sizes 
were kept separate. No difficulty was experienced from firing, although the coal 
was kept in storage until the following winter. This coal was stored for the 
purchaser who paid the actual cost which was found to be slightly over three 
cents for unloading and from seven to eight cents for loading. 

At the Security and Majestic mines in southern Illinois, coal has been stored 
on the ground for the Illinois Central Eailroad by means of side dump cars 
furnished by the road. Whenever the coal companies had no cars for regular 
shipments, these cars were loaded and dumped on the ground near the tipple. 
The coal was reclaimed when needed with locomotive cranes. 

Coal has been similarly stored at Buckner and Christopher, Illinois, by the 
Old Ben Mining Company. At one mine in central Illinois coal was stored in a 
small pond near the tipple and reclaimed with a locomotive crane. 

In the report of the International Kailway Fuel Association for 1915* occur 
the following suggestions for storage at the mines; 

“At strip pit mines practical storage could be accomplished by leaving 
a small covering on the coal. If areas operated were large, from 50,000 to 
100,000 tons could be partially uncovered in the summer and thus carried in 
storage without using the water covering method, and this, I believe, could 
be done at only small additional cost to reimburse the steam shovel operator 
for returning and uncovering and loading coal when season requires. A strip 
pit could be made to double or treble its daily production with only the one 
loading cost, and this would also reduce breakage.” 

This suggestion applies to coal which weathers very quickly, but for coal 
which stands the weather for a reasonable period of time a considerable storage 
capacity may be made available at stripping mines by taking off the surface and 
leaving the coal until it is needed; in fact, it is one of the advantages claimed 
for strip mining. 

A. H. Davies,f Fuel Inspector of the Grand Trunk Pacific Railway, Poca¬ 
hontas, Alberta, Canada, suggests the following system of storage for a mine in 
a hilly country (see Fig. 60): 

‘ ‘ In mountainous districts, where seams are pitching, operators always 
enter the hillside at a point that gives them elevation for their tipple above 
the railroad track, generally about 25 to 30 feet. 

* Proceedings, Vol. VII, p. 265. 
t Ibid. nn. 273-275. 



Ojc^ 


THE STORAGE OF BITUMINOUS COAL 


177 


‘ ‘ At this depth, at foot of sloping hill, adjacent to tipple, a side-cutting 
about eight feet deep, and as long as capacity requires, at one per cent grade, 
dipping away from tipple, should be made. In this cutting construct tunnels 
of ordinary heavy timber, boxed in with round lugging or planking. Then 
bring rock dump at tipple level; parallel with tunnel and opposite the hill. 
The apex of rock dump to be 50 feet from center of tunnel-timber-collar, 
thus forming a V-shaped bin above tunnel. Trim or shear side of rock dump 





/VO 


Fig. 60. Suggested System of Storage for a Mine in a Hilly Country 


(Reproduced from the Proceedings of the International Railway Fuel Association) 



Fig. 61. Suggested System of Storage for Screenings at the Tipple 
(R eproduced from the Proceedings of the International Railway Fuel Association) 


and hillside to an angle of not less than 30 degrees. Cover over with layer 
of ashes, then corduroy, plank, or face with concrete, as desired. Construct 
double track on to storage bin on tipple elevation, one for loads and one for 
empties. From commencement of bin onwards, over and above whole length 
of bin, construct single track. To run on this tracks build a detachable 
traveling carriage dump .... With 25 feet elevation from track in 
tunnel to track on tipple, the capacity would be approximately 2,000 tons per 
one hundred lineal feet of bin. If mine situated on level ground, prairie. 





















178 


ILLINOIS ENGINEERING EXPERIMENT STATION 


elevation is still available in tipple. The only difference would be, that 

another rock pile would have to be constructed, to replace natural hillside. ’ ’ 

Fig. 61 shows a plan suggested for storing screenings at the tipple.* The 
coal is carried from the tipple by a chain bucket conveyor which runs parallel 
with one side of the storage yard, the conveyor being supported on concrete posts, 
and provided with doors every ten feet through which the coal may be dropped 
to the ground, when the bridge bucket places the coal directly in the car standing 
on the loading track independent of the other mine tracks. Such a plan would 
cost more and seems to offer few advantages over the locomotive crane storage 
plant. 

The Consolidation Coal Company!, Fairmont, West Virginia, stores coal in 
its mines in the Miller’s Creek district of eastern Kentucky. The coal is stored 
during the summer time to supply the winter demand and is placed on the ground 
in long, narrow piles about thirty feet high. It is reclaimed by shoveling into 
mine cars. No heating has occurred but the amount of slack increases from thirty 
to fifty per cent. The coal contains about fifty per cent below three-fourths 
inches when stocked. 

47. Storage hy Bailroads .—The subject of railroad storage has been dis¬ 
cussed so fully by the International Railway Fuel Association since 1914 that it 
is very difficult to present any data not already contained in the Proceedings of 
the Association. 

The replies to the questionnaire have brought out the following points; 

The practice of the Illinois Central Railroad! may be summarized as follows: 

The place where coal is to be stored should be free from all rubbish and 
special attention should be paid to drainage to avoid trouble from excessive mois¬ 
ture. The coal in storage should not be in contact with steam pipes. 

It is advisable not to store the coal to a depth exceeding sixteen or eighteen 
feet, nor to a width exceeding thirty feet. Alleyways are left between the stor¬ 
age piles, thus separating the coal in storage into piles about thirty feet long. 

After the storage piles have been completed, pipes, preferably old flues re¬ 
moved from locomotives, are placed at intervals, and staggered about the piles. 
In inserting the pipe into the coal pile a pointed wooded plug is placed in the 
end of the flue, so that it may be driven to the required depth without excessive labor 
The flue should be driven through the coal to within about twenty-four to thirty 
inches of the soil and it should then be withdrawn sufficiently to permit 
the plug to be driven out of the pipe. By inserting a %-inch rod through 
tlie top flue and using a medium hammer the wooden plug can be driven 
out through the bottom, thus creating an air chamber at the bottom of the 
flue in which temperature reading may be taken by means of a thermometer 
fastened to a line. Note of the atmospheric temperature should be made before 
inserting the thermometer into the flue. The thermometer should remain in the 
hole fifteen or twenty minutes. If the temperature of the pile is thirty degrees 


* Ibid, Vol. VI, p. 124, 1914. 
t Frank Haas, Consulting Engineer. 
t H. B. Brown, General Fuel Inspector. 



'HIE STORAGE OP BITUMINOUS COAL 


179 


above that of the atmosphere, that part is immediately taken out and used. Since 
a rapid increase in temperature indicates excessive heat, arrange to remove the 
coal by the use of a locomotive crane or similar mechanical device. 

Do not place fine coal on the bottom of the pile, and keep the bottom dry. 
Mixed screenings will fire more readily than unmixed. 

The alleyways or spaces between the piles give an opportunity to save the coal 
with little expense and provide an easy means of locating trouble from heating. 

Deterioration of coal in storage may be greatly reduced by a covering of small 
coal an inch or less in size. 

Do not mix coals from different mines if it can be avoided, particularly whim 
the action of a given coal in storage has been determined. Screenings particularly 
should not be mixed before storing. Instances are cited of screenings intended for 
power plant use which fired in the car within a short time after having been 
rained on. Locomotive coal from the same mining region which had been stored 
twenty-five years had not fired. 

The following instructions regarding storage of coal on the Rock Island 
Railroad were issued during the spring of 1917 by Carl Scholz, then manager of 
the mining and fuel department, in connection with the contemplated storage of 
465,000 tons of coal at various points, 165,000 tons were to be used to effect car 
economies and to be reloaded after the peak-load of railroad transportation, and 
the rem 9 ,inder to insure an ample supply in case of labor trouble. 

Instructions Governing Storage of Coal 

^‘Engine coal is stored for the purpose of providing fuel at a time when 
the demand for it is greater than the current orders can provide or guard 
against shortage in case of suspension at the mines. 

‘‘In unloading coal, the reloading cost must always be considered, and 
the place selected for storing should be convenient to fuel chutes so as to 
handle coal with the minimum mileage from the storage pile to the place of 
ultimate consumption. 

‘ ‘ In selecting the ground for storage pile, drainings should be fully con¬ 
sidered, because the coal should not be stored on wet ground or filled material 
liable to cause spontaneous combustion. Hard clay is preferable as a founda¬ 
tion, with drainage on both sides, and if necessary, drainage tiles or ditches 
through the center. 

“The 2-inch track unit has been accepted as standard. Under this ar¬ 
rangement, two tracks will be built at sixty-five foot centers. These tracks will 
be raised as the coal is unloaded, so as to rest on the storage pile itself until 
the piles reach their height limit. Then they will be removed and laid at 
fifteen-foot centers between the piles, thereby enabling the reloading of coal, 
either by hand or clam-shell, the clam-shell to travel on one track and the cars 
to be loaded to occupy the other track. 

“Where Illinois and Iowa coals are stored, the coal piles should not ex¬ 
ceed a maximum height of fifteen feet, but with Oklahoma coal the height may 
go to twenty or twenty-two feet. 

‘ ‘ A unit built of this plan of forty cars lengths will store approximately 


180 


ILLINOIS ENGINEERING EXPERIMENT STATION 


35,000 tons of coal. As far as possible, drop bottom cars will be furnished for 
the handling of storage coal. 

‘‘Immediately after heavy rains, it is desirable not to pile fresh coal on 
the stored coal until the moisture has had a chance to evaporate. Care should 
be taken to reject cars containing an unusual amount of slack, and such cars 
should be switched and sent to fuel chutes for immediate consumption, so that 
coarse coal is stored as far as possible. 

‘ ‘ The reloading track which remains on the ground should not be 
covered more than three or four feet above the rails. For the purpose of 
observing any rising temperature, tlues or old pipes should be driven in the 
storage pile every 300 feet so that a thermometer can be suspended therein 
to note any rise in temperature.’’ 

The Central of Georgia Eailway* stores 31,500 tons of Alabama coal four 
inches and under in size, without separating it into sizes or taking out the fine 
coal, about five days after it is mined and keeps it in storage six months. To in¬ 
sure a regular supply and for winter use, coal is stored in July, August, and 
September, because the railroad business is dull and necessary equipment is avail¬ 
able for storage; also the price of coal is usually lower. 

It is placed on the ground in continuous, long, narrow piles limited to fifteen 
feet in height and is reclaimed with a locomotive crane at an expense of 2.58 
cents per ton for storing, and 2.09 cents per ton for reclaiming, including labor 
and supplies. Rental of tracks, depreciation, interest, and insurance are not in¬ 
cluded in these amounts. Coal is thought to decrease in heating value not more 
than five per cent. There was no loss from breakage and no heating. Sixty 
thousand tons stored for six months burned very well. 

The Louisville & Nashville Railroad t has forty-six coaling stations and at 
some of them coal is stored in amounts varying from 50 to 25,000 tons on the 
ground or more generally on a timber floor. It is placed in small bins by hand 
or in large bins by gravity from a trestle or by a locomotive crane from cars. A 
circular system is also used. It is reclaimed by locomotive crane or by hand. 

The height of the pile depends upon the coal used, being limited in some 
cases to twelve feet and in others reaching to more than twenty feet without 
heating. In case of heating, the coal is removed or sprinkled with water. Coal is 
kept in storage indefinitely and is stored during the summer to take advantage of 
the low price, to relieve car service in winter, and to insure supply. Sizes are not 
kept separate and fine coal is not removed. The heating value is thought to de¬ 
crease and the extent to which coal will heat depends upon the height of the 
pile and the condition of the coal when received. 

The Baltimore & Ohio Railroadt is using industrial tracks, which are elevated 
or are raised on cribs, to store on the ground run of mine coal from Somerset, 
Pennsylvania. In this way cars are released promptly. The coal is reclaimed with 
a locomotive crane and there is only a slight loss in heating value and a slight 
breakage loss. 


* A. P. Wells, Engineer of Tests. 

t Engineering Record, 1914-15, Engineering News, 1914-15. 
i W. H. Averell, General Manager. 



THE STORAGE OP BITUMINOUS COAL 


181 


The Chicago & Northwestern Eailroad* stores from 12,000 to 40,000 tons of 
coal from Macoupin County, Illinois, generally storing the six-inch lump, and using 
the fine coal at once. Run of mine has also been stored. Continuous piles not 
over twelve-feet high are used with tubes placed for temperature observations and 
the piles are very closely watched. This method has been tried for four years and 
if deterioration occurs it is mostly during the first few months and not after one 
year. 

The Southern Railway System t stores about 10,000 tons of Illinois and 
Kentucky screened coal at Danville, Kentucky, 18,000 tons at Huntington, Indiana, 
and also from 60,000 to 180,000 tons of coals from Middlesboro, Kentucky, and 
southwest Virginia. These are stored within two to twenty days after being 
mined and are kept in storage from four to eight months. The coal is stored on 
the ground in continuous piles from ten to fourteen feet high. The slack is not' 
removed and the sizes are not kept separate. There is thought to be a ten per cent 
decrease in heating value and a breakage loss of fifteen per cent. The coal some¬ 
times heats but it has never fired. The piles are limited to a height of fourteen 
feet. If heating occurs, the coal is picked up and used immediately, or is spread 
out and allowed to cool. Goodwin says: ‘ ‘ Theoretically, there is little decrease in 

heating value, but practically, on account of the slack present, we do not get the 
same results from stored coal as from fresh.” 

The Michigan Central Railroad t had in storage at Gary, Indiana, during the 
summer of 1917, 35,000 tons of 1%-inch lump and run of mine coal from West 
Clinton, Indiana, and from Harrisburg and Freeburg, Illinois. The sizes were not 
kept separate and the slack was not removed. The coal was stored from five to 
fifteen days after being mined. It was placed on the ground by hand or by clam¬ 
shell buckets in long piles eighteen feet deep. This coal had been in storage for 
four or five months when it took fire, although at other times coal had been kept 
from eight to eighteen months without firing. Where the fire started, the pile was 
not more than twelve feet high. At the point of firing there was found to be a 
quantity of very dry fine slack. The moisture had evidently been dried out by the 
heat from below, since the coal above this spot was damp and this dampness evi¬ 
dently came from the moisture being driven from the coal below. Where the coal 
fired it was lumpy or coarse, and coyered with very fine slack. Apparently the 
slack retained the heat and did not permit it to radiate, so that the temperature 
gradually rose to the ignition point. After the fires had been dug out the remaining 
coal cooled and since then no fires or extreme heat have been noticed. 

The Chicago, Lake Shore & South Bend RailroadH stores about 3,000 tons of 
coal from Clinton, Indiana, on the ground in continuous piles about fourteen feet 
high. The sizes are kept separate in storage and slack is removed. The coal is 
stored two weeks after being mined and, if possible, is placed in storage between 
the first of September and the first of December because of the prevailing favorable 


*W. E. Dunham, Supervisor of Motive Power, 
t C. G. Goodwin, Fuel Agent, 
t J, C. Dougherty, Coal Inspector. 

n W. E. Bolston, Superintendent of Power and Equipment. 



182 


ILLINOIS ENGINEERING EXPERIMENT STATION 


weather conditions during that period. It is kept in storage about one year. There 
is a slight decrease in heating value and heating is likely to occur in from one to 
six months. In case of heating, the coal is removed at once. To avoid heating, the 
piles are kept small and low in height. The coal is handled by means of a locomo¬ 
tive crane at a cost of twelve cents per ton for storing and reclaiming. 

Chicago, Burlington & Quincy Railroad* had in storage October 1, 1917, 
562,000 tons of coal, which were stored between April and September. This coal 
was intended for use in November and December. The experience of the Burling¬ 
ton as given by Crawford is summarized as follows: 

At Havelock, Nebraska, there were stored 8,000 tons of coal from the Virden, 
Illinois, district in long piles from twelve to fifteen feet high and forty-two feet 
wide. The coal was stored early in June and about July 30 was reported to be 
.heating throughout. Although the company began to load out the coal at once, 
heating continued to spread rapidly and on August 16 a pipe was laid to the pile 
which was spread out so that the coal was only from three to five feet thick and 
water was put on it day and night; consequently it is stated that only five per 
cent of the coal was lost. In other piles at Galesburg and Savanna, Illinois, 
there was similar trouble from firing. 

At Clyde, Illinois, southern Illinois screenings were stored and where fires 
occurred, Crawford attributes them to excessive depth of piles. The general policy 
of the Burlington is to store from April to September, and where two coals from 
different districts are stored at the same point, to keep the different coals in sepa¬ 
rate piles. Egg and lump coals are not separated, but where the storage coal is 
to be handled with a clam-shell directly upon an engine, it is advisable to store 
only egg coal. Coal should be stored in as dry weather as possible. Superinten¬ 
dents are advised to store coal on ground reasonably level and as high as possible 
from which rubbish has been removed, and not over steam lines. 

Crawford states: 

‘^I think every one should figure that there is going to be heating in 
storage coal and should provide full means for dissipating that heat. The 
only way I know of to stop this heating in coal storage is to store the coal low 
enough, and be careful to store lump and egg coals so that there will be 
reasonably free circulation. 

“It is impracticable for a railroad to allow coal to season in a car, and a 
better way to let it season is to store it in long piles, building it up gradually. 
Here, however, we come to the point of the advisability of putting freshly 
mined coal upon a pile of coal already stored which has been subjected to the 
rays of the sun when the temperature is around 100 degrees. In other words, 
I think the fresh coal will pick up more heat from a pile of storage coal than 
it would from the ground. 

‘ I am satisfied that by carefully inspecting the Belleville district coal 
going into the North St. Louis pile which is seventeen feet high that we 
saved a fire at this point. The mines started to ship us mine run billed lump 
and fortunately we discovered this in time and placed an inspector in the 
district .' ’ 

* J. G. Crawford, Fuel Engineer. 



THE STORAGE OF BITUMINOUS COAL 


183 


The Missouri, Kansas & Texas Railroad* stores Illinois 2-inch lump coal from 
the Belleville district, coal from the Pittsburgh district, Kansas, with twenty-five 
per cent of the slack removed, called modified lump, mine run coal from the Mc- 
Alester district, Oklahoma, and also coal from Thurber, Texas. The coal is kept 
in storage from six months to one year. Different varieties, and different sizes 
are piled separately. It has been found, that coal from the McAlester district, 
Oklahoma, will fire when mixed with coal from the Lehigh district, Oklahoma. 
The slack is removed except where Oklahoma mine run is stored. As much time 
as possible is recommended between the mining and storing, and March, April, 
May, and September are considered the best months in which to store. There is 
thought to be a slight loss in heating value and a slight breakage loss. Hibben 
summarizes his practice as follows: 

‘ ‘ Heating depends upon the manner in which the coal is stored and the 
kinds of coal. It is not wise to store fine coal and lump should be used, if 
possible. Do not pile over fifteen feet high. The cost of storing with clam¬ 
shell buckets has been 3^ cents per ton which includes the cost of con¬ 
struction of new track when necessary, the salary of the operator and other 
necessary employees to remove the coal left in the car. The estimated cost 
for reclaiming is the same. ’ ’ 

C. M. Butler, of the Atlantic Coast Line, said at the 1917 meeting of the 
Railway Fuel Association: 

‘ ‘ There will be a week or ten days when from certain coal supplies we 
do not receive a single car. That is not due to the fact that the mines have 
not been shipping it, but it is due to the fact that railroad companies handling 
the coal from the mines to us have been unable to get it to us. Then there is 
another week when we will get three times as much coal as we need. The result 
is that we have a surplus of coal loaded in cars, and in order to help the 
situation we have made some arrangements to release that coal regardless of 
consumption. We have made places all over our line to store coal, and to 
store coal this week and use it next and restore it in the same place and pick 
it up, simply to release the cars. I feel sure that our own little supply has 
been very much helped by our prompt handling of the cars; not only from 
the fact that we have put those cars back to the mines to be reloaded, but we 
have created a feeling at the mines where our coal is loaded that any coal 
allotted to us will receive prompt attention and the cars will not be held in¬ 
definitely. ’ ’ 

The Atlantic Coast Line keeps Virginia and West Virginia run of mine, high 
volatile coals in storage for six months without separating the sizes and with¬ 
out removing the slack, there being from fifty to sixty per cent slack below % 
inches in the coal when stored. Some of the piles are continuous and some are 
partitioned into sections. The coal is stored in August and September, before the 
heavy fall traffic, and is placed in semicircular piles, twenty-five feet high, by 
means of a locomotive crane which takes the coal from a pit. If stored in a wet 
place or in a high pile, the coal heats very soon after being stored. The expenditure 


* R. R. Hibben, Assistant Fuel Agent. 



184 


ILLINOIS ENGINEERING EXPERIMENT STATION 


for labor, operation, repairs, and maintenance varies from four to five cents per 
ton, depending upon the appliances used. 

The Grand Trunk Pacific Eailroad* stored 150,000 tons of Ohio and Pittsburgh 
No. 8 coal over % inches in size and 40,000 tons of Jasper Park Alberta mine run 
coal containing 70‘per cent below % inches on the ground in continuous piles 
twenty-four feet high by laying a track on top of the pile as it is gradually built up. 
It is reclaimed by hand, by a clam-shell bucket, and occasionally also by a ditcher. 
It is stored during the dry months when the coal is available and usually about 
three weeks after mining. It has been in storage from one to five years with little 
firing, no appreciable deterioration in heating value, and little degradation, but 
this is stored in a cold climate. The expenditure for labor and supplies is eight 
cents per ton for stocking, and 6.2 cents for reclaiming. 

The accompanying illustrations (Figs. 62 and 63) show a coal pile stored by 
the C. C. C. & St. L. R. R., near Hillary, Illinois, west of Danville. About 30,- 
000 tons of run of mine. No. 7 coal were stored, in from one to three days after 
being mined, in two piles and to a depth of from fifteen to twenty feet by means 
of tracks on top of the piles. (See also Figs. 6 and 7 on page 45). No attempt was 
made to remove the fine coal. Most of the fine coal fell on the north side of the 
pile and the lump on the south side. In the east pile pipes were placed and tempera¬ 
ture readings taken daily at points, 5, 10, 15, and 20 feet from the top. The log of 
these readings as given by P. T. White, Superintendent of the C. 0. C. & St. L. 
R. R., is presented as Table 7. A temperature of 170 degrees was recorded shortly 
before the fire broke out in the pile, the highest temperature being recorded 
usually five feet below the top of the pile. Fire broke out after several days of 
intensely hot weather, which were followed by heavy thunder storm and then by 
more days of hot humid weather. The starting of the fire in the west pile is shown 
in Fig. 62 and the same fire a few days afterwards is shown in Fig. 63. 

The appearance of the pile at one point after the burning coal had been 
loaded out is showm in Fig. 63, which shows that there was a large amount of 
very fine coal. As the hot and steaming coal was loaded out, it was quenched with 
water and used immediately. P. T. White, Superintendent of the Big Four, says: 

‘‘One place where the storage pile was burning we smothered with dirt 
and two days later on opening this place up with the steam shovel, we 
found the coal at an intense white heat, fire extending for about six feet into 
the pile. I am inclined to believe that our trouble this year is due to the 
great quantities of impurities and slack in the coal and to the peculiar weather 
conditions that prevailed just previous to the fire. I am of the opinion that 
successful storing of coal demands that coal be reasonably free from impurities 
and slack. 

The C. C. C. & St. L. R. R. also had fire in coal at Beech Grove, Springfield, 
and Bellefontaine, Ohio, and Mattoon, Illinois, stored similarly to that at Hillary. 


* T. Duff Smith, Fuel Agent. 



Fig. 62. Coal Pile of the C. C. C. and St. L. R. R. near Hillary, Illinois 

This pile contained about 30,000 tons of no. 7 Run of Mine Coal 
WHICH fired in the SUMMER OF 1917 































Fig. 63. Another View of the Burning Coal Pile of the C. C. C. and St. L 
R. R. NEAR Hillary, Illinois, in the summer of 1917 




































I'Vest pile fired. Note;—No temperature taken between July 19 and 24, on account of thermometer being broken. 

East pile fired August 14. 


THE STORAGE OF BITUMINOUS COAL 


187 


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Temperature of Coal Stored at Hillary, Illinois, by 














































LIST OF 

PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION 


Bulletin No. 1. Tests of Reinforced Concrete Beams, by Arthur N. Talbot. 1904. None available. 

Circular No. 1. High-Speed Tool Steels, by L. P. Breckenridge. 1905. None available. 

Bulletin No^ 2. Tests of High-Speed Tool Steels on Cast Iron, by L. P. Breckenridge and Henry 
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Circular No. 2. Drainage of Earth Roads, by Ira O. Baker. 1906. None available. 

Circular No. 3. Fuel Tests with Illinois Coal (Compiled from tests made by the Technological 
Branch of the U. S. G. S., at the St. Louis, Mo., Fuel Testing Plant, 1904—1907), by L. P. Breckenridge 
and Paul Diserens. 1908. Thirty cents. 

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1906. Forty-five cents. 

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None available. 

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Bulletin No. 7. Fuel Tests with Illinois Coals, by L. P, Breckenridge, S. W. Parr, and Henry B. 
Dirks. 1906. None available. 

Bulletin No. 8. Tests of Concrete: I, Shear; II, Bond, by Arthur N. Talbot. 1906. None 
available. 

Bulletin No. 9. An Extension of the Dewey Decimal System of Classification Applied to the 
Engineering Industries, by L. P. Breckenridge and G. A. Goodenough. 1906. Revised Edition 
1912. Fifty cents. 

Bulletin No. 10. Tests of Concrete and Reinforced Concrete Columns, Series of 1906, by Arthur 
N. Talbot. 1907. None available. 

Bulletin No. 11. The Effect of Scale on the Transmission of Heat through Locomotive Boiler 
Tubes, by Edward C. Schmidt and John M. Snodgrass. 1907. None available. 

Bulletin No. 12. Tests of Reinforced Concrete T-Beams, Series of 1906, by Arthur N. Talbot. 

1907. None available. 

Bulletin No. 13. An Extension of the Dewey Decimal System of Classification Applied to Archi¬ 
tecture and Building, by N. Clifford Ricker. 1907. None available. 

Bulletin No. I 4 . Tests of Reinforced Concrete Beams, Series of 1906, by Arthur N. Talbot. 

1907. None available. 

Bulletin No. 15. How to Burn Illinois Coal Without Smoke, by L. P. Breckenridge. 1908' 
None available. 

Bulletin No. 16. A Study of Roof Trusses, by N. Clifford Ricker. 1908. None available. 

Bulletin No. 17. The Weathering of Coal, by S. W. Parr, N. D. Hamilton, and W. F. Wheeler. 

1908. None available. 

Bulletin No. 18. The Strength of Chain Links, by G. A. Goodenough and L. E. Moore. 1908 
Forty cents. 

Bulletin No. 19. Comparative Tests of Carbon, Metallized Carbon and Tantalum Filament 
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N. Talbot. 1908. None available. 

Bulletin No. 21. Tests of a Liquid Air Plant, by C. S. Hudson and C. M. Garland. 1908. Fifteen 
cents. 

Bulletin No. 22. Tests of Cast-Iron and Reinforced Concrete Culvert Pipe, by Arthur N. Talbot. 
1908. None available. 

Bulletin No. 23. Voids, Settlement and Weight of Crushed Stone, by Ira O. Baker. 1908. 
Fifteen cents. 

* Bulletin No. 24. The Modification of Illinois Coal by Low Temperature Distillation, by S. W. Parr 
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Bulletin No. 25. Lighting Country Homes by Private Electric Plants, by T. H. Amrine. 1908. 
Twenty cents. 

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189 




190 


PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION 


Bulletin No. 26. High Steam-Pressures in Locomotive Service. A Review of a Report to the 
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Bulletin No. 27. Tests of Brick Columns and Terra Cotta Block Columns, by Arthur N. Talbot 
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Bulletin No. 29. Tests of Reinforced Concrete Beams: Resistance to Web Stresses, Series of 
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*Bulletin No. SO. On the Rate of Formation of Carbon Monoxide in Gas Producers, by J. K. Cle¬ 
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*Bulletin No. 31. Tests with House-Heating Boilers, by J. M. Snodgrass. 1909. Fifty-five 
cents. 

Bulletin No. 32. The Occluded Gases in Coal, by S. W. Parr and Perry Barker. 1909. Fifteen 
cents. 

Bulletin No. S3. Tests of Tungsten Lamps, by T. H. Amrine and A. Guell. 1909. Twenty cents. 

*Bulletin No. 34- Tests of Two Types of Tile-Roof Furnaces under a Water-Tube Boiler, by J. M. 
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Bulletin No. 36. The Thermal Conductivity of Fire-Clay at High Temperatures, by J. K. Clement 
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*Bulletin No. 38. The Weathering of Coal, by S. W. Parr and W. F. Wheeler. 1909. Twenty- 
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*Bulletin No. 39. Tests of Washed Grades of Illinois Coal, by C. S. McGovney. 1909. Seventy- 
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Bulletin No. 40. A Study in Heat Transmission, by J. K. Clement and C. M. Garland. 1910. 
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Bulletin No. 41- Tests of Timber Beams, by Arthur N. Talbot. 1910. Thirty-five cents. 

*Bulletin No. 4^- The Effect of Keyways on the Strength of Shafts, by Herbert F. Moore. 1910. 
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*Bulletin No. 45. The Strength of Oxyacetylene Welds in Steel, by Herbert L. Whittemore. 1911. 
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*Bulletin No. 43. The Spontaneous Combustion of Coal, by S. W. Parr and F. W. Kressman. 
1911. Forty-five cents. 

*Bulletin No. 47. Magnetic Properties of Heusler Alloys, by Edward B. Stephenson, 1911. Twen¬ 
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*Bulletin No. 48. Resistance to Flow Through Locomotive Water Columns, by Arthur N. Talbot 
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*Bulletin No. 49. Tests of Nickel-Steel Riveted Joints, by Arthur N. Talbot and Herbert F. Moore. 
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191 


T ^ New Analysis of the Cylinder Performance of Reciprocating Engines, by 

J. Paul Clayton. 1912. Sixty cents. 

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Bulletin No. 66. The Properties of Saturated and Superheated Ammonia Vapor, by G. A. Good- 
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192 


PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION 


^Bulletin No. 89. Specific Gravity Studies of Illinois Coal, by Merle L. Nebel. 191G. Thirty 
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Bulletin No. 91. Subsidence Resulting from Mining, by L. E. Young and H. H. Stock. 1916* 
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Circular No. 4- The Economical Purchase and Use of Coal for Heating Homes, with Special 
Reference to Conditions in Illinois. 1917. Ten cents. 


^Bulletin No. 99. The Collapse of Short Thin Tubes, by A. P. Carman. 1917. Twenty cents 

^Circular No. 5. The Utilization of Pyrite Occurring in Illinois Bituminous Coal, by E. A. 
Holbrook. 1917. Twenty cents. 

*Bulletin No. 100. Percentage of Extraction of Bituminous Coal with Special Reference to Illinois 
Conditions, by C. M. Young. 1917. 

*Bulletin No. 101. Comparative Tests of Six Sizes of Illinois Coal on a Mikado Locomotive, by 
E. C. Schmidt, J. M. Snodgrass, and O. S. Beyer, Jr. 1917. Fifty cents. 

* Bulletin No. 102. A Study of the Heat Transmission of Building Materials, by A. C. Willard 
and L. C. Lichty. 1917. Twenty-five cents. 

*Bulletin No. 103. An Investigation of Twist Drills, by Bruce W. Benedict and W. P. Lukens. 
1917. Sixty cents. 

*Bulletin No. 104- Tests to Determine the Rigidity of Riveted Joints of Steel Structures by 
W. M. Wilson and H. F. Moore. 1917. Twenty-five cents. 

Circular No. 6. The Storage of Bituminous Coal, by H. H. Stoek. 1918. Forty cents. 


*A limited number of copies of bulletins starred is available for free distribution. 






THE UNIVERSITY OP ILLINOIS 
THE STATE UNIVERSITY 
Urbana 

Edmund J. James, Ph. D., LL. D., President 


THE UNIVERSITY INCLUDES THE FOLLOWING DEPARTMENTS: 
The Graduate School 

The College of Liberal Arts and Sciences (Ancient and Modem Languages and 
Literatures; History, Economics, Political Science, Sociology; Philosophy, 
Psychology, Education; Mathernatics; Astronomy; Geolo^; Physics; Chemistry; 
Botany, Zoology, Entomology; Physiology; Art and Design) 

The College of Commerce and Business Administration (General Business, Bank¬ 
ing, Insurance, Accountancy, Railw^ Administration, Foreign Commerce; 
Courses for Commercial Teachers and Commercial and Civic Secretaries) 

The College of Engineering (Architecture; Architectural, Ceramic, Civil, Electrical, 
Mechanical, Mining, Municipal and Sanitary, and Railway Engineering) 

The College of Agricixlture (Agronomv; Animal Husbandly Dai^ Husbandry: 
Horticulture and Landscape Gardening; Agricultural Extension; Teachers’ 
Course; Household Science) 

The College of Law (three years’course) 

The School of Education 

The Course in Journalism 

The Courses in Chemistry and Chemical Engineering ^ 

The School of Railway Engineering and Administration 
The School of Music (four years’ course) 

The School of Library Science (two years’ course) 

■- fla ■ 

The College of Medicine (in Chicago) 

The College of Dentistry (in Chicago) 

The School of Pharmacy (in Chicago; Ph, G. and Ph, C. courses) 

The Summer Session (eight weeks) 

Experiment Stations and Scientific Bureaus: U. S. Agricultural Experiment 
Station; Engineering Experiment Station; State Laboratory of Natural His^ 
tory; State Entomologist’s Office; Biological Experiment Station on Illinois 
River; State Water Survey; State Geological Survey; U. S. Bureau of Mines 
Experiment Station. 

The library collections contain (December 1, 1917) 411,737 volumes and 104,524 
pamphlets. 

For catalogs and information address 



THE REGISTRAR 

Urbana, Illinois 







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